EP0061446B1 - Chemically sensitized silver halide photographic emulsions and color photographic elements containing said emulsions - Google Patents

Chemically sensitized silver halide photographic emulsions and color photographic elements containing said emulsions Download PDF

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Publication number
EP0061446B1
EP0061446B1 EP19810901016 EP81901016A EP0061446B1 EP 0061446 B1 EP0061446 B1 EP 0061446B1 EP 19810901016 EP19810901016 EP 19810901016 EP 81901016 A EP81901016 A EP 81901016A EP 0061446 B1 EP0061446 B1 EP 0061446B1
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EP
European Patent Office
Prior art keywords
silver halide
emulsions
photographic
photographic emulsion
aromatic
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
Application number
EP19810901016
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German (de)
English (en)
French (fr)
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EP0061446A1 (en
EP0061446A4 (en
Inventor
Paolo Beretta
Guglielmo Izzi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
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Filing date
Publication date
Application filed by Minnesota Mining and Manufacturing Co filed Critical Minnesota Mining and Manufacturing Co
Publication of EP0061446A1 publication Critical patent/EP0061446A1/en
Publication of EP0061446A4 publication Critical patent/EP0061446A4/en
Application granted granted Critical
Publication of EP0061446B1 publication Critical patent/EP0061446B1/en
Expired legal-status Critical Current

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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
    • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising

Definitions

  • the present invention relates to the use of certain compounds useful as sulfur sensitizers for silver halide photographic emulsions associated with color couplers for use in color photography.
  • the present invention refers to silver halide photographic emulsions associated with color couplers sensitized with a particular class of sulfur sensitizer compounds and to photographic elements containing said emulsions.
  • Silver halide photographic emulsions are generally prepared by precipitating small silver halide crystals in the presence of a protective colloid, e.g. gelatin.
  • the crystals obtained upon precipitation are grown to the required grain size (ripened) by heating them for a given period of time in the presence of a silver halide solvent.
  • the so prepared photographic emulsion inherently has a rather low light sensitivity.
  • the ripened emulsion is reacted with chemical sensitizers, i.e. with compounds capable of forming sensitivity centers on the grains.
  • Compounds capable of forming sensitivity centers are usually characterized by the presence of one or more sulfur atoms, capable of forming complexes with the silver halide which can decompose into silver sulfide.
  • This sulfiding operation is called chemical digestion, and typical sulfur sensitizers, which can be present in gelatin as impurities or can be deliberately added to the emulsion, are for instance thiosulfate, allylisothiourea, thiourea and 2-thio- succinimide.
  • the sensitivity center formation in addition to the sensitivity increase, involves also other changes in the photographic properties of the emulsion, among which the most serious is fog. This phenomenon occurs in a certain percentage of crystals which are developable without exposure to light. During chemical digestion, sensitivity centers are prevalently formed, but at the same time fog centers are also formed.
  • sensitivity reaches an optimal value at a given digestion time; once that this time has been exceeded, sensitivity starts decreasing while fog density continues to increase.
  • a fog increase is caused even before the emulsion reaches the flat portion of the ripening curve and therefore before the desired reactivity is reached.
  • chemical digestion is performed until the required sensitivity is obtained, and fog is reduced and controlled by means of antifoggants, i.e. substances which should have the property of decreasing fog more than sensitivity.
  • antifoggants i.e. substances which should have the property of decreasing fog more than sensitivity.
  • these substances have the drawback of also reducing to a certain extent the sensitivity and the reactivity of the sensitive layer.
  • antifoggants being adsorbed by the silver halide crystals, may interfere with the other operations which are important in the photographic layer.
  • these emulsions are associated with non diffusing-couplers which in the presence of exposed silver halide are capable of reacting with p-phenylene. diamine developers to form a dye image-wise distributed in the developed photographic element.
  • Such non-diffusing couplers can be introduced into the photographic layer containing them (generally the silver halide emulsion layer or a layer adjacent thereto) either in an aqueous alkaline solution (in this case at least an acid solubilizing group of the S0 3 H or COOH type must be introduced into the coupler molecule itself), or dissolved in a high-boiling solvent dispersed in the coating composition of the layer itself.
  • an aqueous alkaline solution in this case at least an acid solubilizing group of the S0 3 H or COOH type must be introduced into the coupler molecule itself
  • a high-boiling solvent dispersed in the coating composition of the layer itself in a high-boiling solvent dispersed in the coating composition of the layer itself.
  • this second method which at present is the preferred one, is called “dispersion method” and substantially consists of first dissolving the coupler in a substantially water-immiscible organic solvent and then dispersing the so-obtained solution as extremely tiny droplets into a hydrophilic colloidal binder.
  • Gelatin is the preferred hydrophilic colloidal binder, but other known polymeric colloidal binders can also be used. (A description of the dispersion method can be found in U.S. Patents 2,322,027; 2,801,170; 2,801,171 and 2,991,177).
  • U.S. Patent 3,859,100 discloses the use of at least one triazaindene, tetraazaindene or pentaazaindene having at least one hydroxy group and at least one compound having a 1,2-dithiolane or a 1,2-dithiane ring to reduce fog without a reduction in desirable photographic characteristics.
  • the problem of fog associated with the high reactivities of the materials is particularly delicate since the product can hardly tolerate fog values even only slightly higher than the natural minimum ones (which substantially correspond to the supporting base fog) while at the same time the reactivity of the exposed emulsions associated with the couplers tends to be difficult to control during the color development with p-phenylene diamine developer.
  • new agents are provided for chemically sensitizing the silver halide emulsion associated with color couplers, which agents have the following formulas: or mixtures thereof, wherein R is a hydrogen atom, aliphatic group or an aromatic or non-aromatic cyclic nucleus and R' is a hydrogen atom, an aliphatic group or an aromatic or non-aromatic cyclic nucleus, at least one of them being different from hydrogen.
  • a preferred aromatic nucleus is a phenyl group unsubstituted or substituted with an alkyl or an alkoxy group having no more than 4 carbon atoms or with a halogen substituent, preferably chlorine, as for example, phenyl, p-methoxy-phenyl, p-chloro-phenyl.
  • a preferred cyclic non aromatic nucleus (saturated or not saturated) is a cyclohexyl or cyclohexenyl group.
  • R and R' are both alkyl groups having from 1 to 4 carbon atoms, and most preferably they are methyl groups.
  • the present invention refers to a silver halide photographic emulsion associated with color couplers for the use in photography to obtain dye images and containing a sensitizing amount of sulfur sensitizer characterized in that the sulphur sensitizer is a 1,2,4-dithiazolidino-3-thione sulfur sensitizer corresponding to the formula: or a dimethylenetrisulfide sulfur sensitizer corresponding to the formula: or mixture thereof, wherein R is n aliphatic chain, preferably having no more than 4 carbon atoms, or a cyclic aromatic or non-aromatic nucleus, preferably a 5 or 6 membered nucleus, at least R or R' being different from hydrogen.
  • the sulphur sensitizer is a 1,2,4-dithiazolidino-3-thione sulfur sensitizer corresponding to the formula: or a dimethylenetrisulfide sulfur sensitizer corresponding to the formula: or mixture thereof, wherein R is n aliphatic chain, preferably having no
  • the present invention refers to a photographic emulsion, as described above, wherein both R and R' are methyl groups.
  • the present invention refers to a photographic emulsion, as described above, containing also a sensitizing amount of a noble metal salt, such as a gold sensitizer.
  • a noble metal salt such as a gold sensitizer.
  • the present invention further refers to a photographic.element including a supporting base and a silver halide emulsion associated with a coupler and containing a sensitizing amount of a sulfur sensitizer, characterized in that the sulfur sensitizer is as described above.
  • the present invention in a further aspect refers to a method for manufacturing a silver halide photographic emulsion for use in color photography which includes the addition of at least one sulfur sensitizing compound, characterized in that the sulfur sensitizing compound is as hereinbefore defined and that the defined sulfur sensitizing compound can be added to the silver halide emulsion prior to or during the chemical digestion and the subsequent aadition of a color coupler prior to the coating of the obtained photographic composition.
  • the optimal quantity of sulfur sensitizer used in the present invention depends upon the specific compound which is used, upon the nature of the colloidal binding agent for the silver halide crystals, upon the quantity, type and size of the silver halide crystals, upon the digestion time and temperature and upon the emulsion pH and pAg-values. We have found they can be used in a quantity ranging from 0.001 to 0.25 millimoles, preferably from 0.01 to 0.1 millimoles, per mole of silver.
  • the new sulfur sensitizers of the present invention can be used in combination with other sensitizers known in the art, such as e.g. gold salts.
  • other sensitizers known in the art such as e.g. gold salts.
  • This product was prepared according to example 4, using 4-chloro-phenyl-isothiocyanate and ligroin as solvent.
  • This compound was prepared according to example 6, using propionic anhydride instead of acetic anhydride.
  • This compound was prepared according to example 1, using 4-methoxy-phenyl-isothiocyanate instead of phenylisothiocyanate.
  • the silver halide emulsion type which can be chemically digested according to the present invention is not critical.
  • the emulsion can be a silver chloride, a silver iodide, a silver chloro-bromide, a silver chloro-iodide, a silver bromo-iodide, or a silver chlorobromo-iodide emulsion.
  • the preparation and the types of emulsions which can be used for the present invention are for instance those described in research Disclosure, vol. 176, December 1978, item 17643 1.
  • the silver halide emulsions can be unwashed or washed to remove the soluble salts, as for instance described in Research Disclosure, vol.
  • the silver halide emulsions can be also chemically sensitized with active gelatins, noble metal salts or with reducing substances, as described in Research Disclosure, vol. 176, December 1978, item 17643 III.
  • the silver halide emulsions can be spectrally sensitized with dyes of various classes, among which there is the polymethine dye class, which includes cyanines, merocyanines, complex cyanines and merocyanines, oxonoles, hemioxonoles, styryls, merostyryls, and streptocyanines, as described in Research Disclosure, vol.
  • Optical brightners can be employed in the photographic element which include said emulsions, as those decribed in Research Disclosure, vol. 176, December 1978, item 17643 V.
  • the instability which increases the minimum density (i.g. fog) in negative-type emulsion coatings or which decreases the maximum density in direct-positive emulsion coatings, can be avoided by adding stabilizers, antifoggants, antikinking agents, latent-image stabilizers and the like to the emulsions and adjacent layers prior to coating, as described in Research Disclosure, vol. 176, December 1978, item 17643 VI.
  • the dye forming couplers which are to be associated with the photographic emulsion of the present invention, are chosen to form substractive primary (i.e. yellow, magenta and cyan) image dyes and are non-diffusible, colorless couplers, such as two and four-equivalent couplers of the open-chain ketomethylene, pyrazolone, phenol and naphtol type.
  • Such couplers are for example described in Research Disclosure, vol. 176, December 1978, item 17643 VII D and E.
  • the photographic element can incorporate colored dye forming couplers, such as those employed to form integral masks for negative color images, as illustrated in Research Disclosure, vol. 176, December 1978, item 17643 VII G.
  • the dye forming couplers can release upon coupling photographically useful fragments, such as development inhibitors or accelerators, bleach accelerators, hardeners and so on, as described in Research Disclosure, vol. 176, December 1978, item 17643 VII F.
  • the above dye forming couplers can be incorporated in the photographic element, as described in Research Disclosure, vol. 176, December 1978, item 17643 VII C.
  • Incident and reflected radiation can be absorbed or scattered by incorporating materials for that purpose in the photographic element layers. Reflective or absorbing materials incorporated directly in the silver halide emulsion layers can increase speed or sharpness.
  • Filter materials typically located in overcoat and interlayers, can trim spectrally or attenuate incident radiation and antihalation materials, typically located in undercoat and backing layers, can eliminate or diminish reflection (halation) exposure of emulsion layers.
  • Reflective and absorbing materials are for instance those described in Research Disclosure, vol. 176, December 1978, item 17643 VIII;
  • Photographic silver halide emulsion layers and other layers on photographic elements can contain various colloids alone or in combination as vehicles, as described for instance in Research Disclosure, vol. 176, December 1978, item 17643 IX.
  • the layers of the photographic element containing cross-linkable colloids, particularly the gelatin-containing layers, can be hardened by various organic and inorganic hardeners, as those described in Research Disclosure, vol.
  • the photographic element layers can contain various types of coating aids, such as anionic, cationic, non-ionic or zwitterionic surfactants, alone or in combination, as those described in Research Disclosure, vol. 176, December 1978, item 17643 XI.
  • coating aids such as anionic, cationic, non-ionic or zwitterionic surfactants, alone or in combination, as those described in Research Disclosure, vol. 176, December 1978, item 17643 XI.
  • the flexibility of the photographic element layers upon drying can be improved through the incorporation of plasticizers, as described in Research Disclosure, vol. 176, December 1978, item 17643 XII A.
  • the photographic element can contain lubricants to reduce sliding friction encountered in use, as described in Research Disclosure, vol. 176, December 1978, item XII B.
  • the photographic element can contain conducting layers, such as antistatic layers, as described in Research Disclosure, vol.
  • the sensitizing dyes and the other addenda incorporated into the layers of the photographic element can be dissolved and added prior to coating either from water or organic solvent solutions, by following various techniques as described in Research Disclosure, vol. 176, December 1978, item 17643 XIV.
  • the layers can be located on the photographic element the layers can be located on the photographic support by various procedures, as described in Research Disclosure, vol. 176, December 1978, item 17643 XV A.
  • the coated layers of the photograhic element can be dried by various procedures, as described in Research Disclosure, vol. 176, December 1978, item XV B.
  • the layers of the photographic element can contain matter agents, as for instance described in Research Disclosure, vol.
  • the layers of the photographic element can be coated on a variety of supports provided with one or more layers to enhance the adhesive, antistatic dimensional, abrasive, hardness, frictional, antihalation and/or other properties, as described in Research Disclosure, vol. 176, item 17643 XVII.
  • the light sensitive silver halide contained in the photographic element can be processed following exposure to form a visible image by associating the silver halide with an aqueous alkaline medium in the presence of a developing agent contained in the medium or element with a variety of formulations and techniques, as described in Research Disclosure, vol. 176, December 1978, item 17643 XIX.
  • a gelatin silver chloro-bromide emulsion containing 72% mole silver chloride and 28% mole silver bromide was prepared in the usual way and coagulated by means of carbamoyl gelatin. The coagulum was redispersed in gelatin solution at 57°C with a silver-to-gelatin ratio of 0.38.
  • a gelatin silver halide emulsion containing 85% mole silver bromide, 14% mole silver chloride and 1 % mole silver iodide has been prepared by the double jet technique and then coagulated by means of carbamoyl gelatin.
  • the digested emulsion samples were added with the coating aids, yellow coupler a - pivalyl - a - (3 - chloro - 1,2,4 - triazolyl) - 5 - [a - (2,4 - ditert. - amylphenoxy) - butyramido] - 2 - chloro - acetanilide dispersion and coated on a triacetate base with a silver covering weight of 0.80 g/m 2 .
  • the antifog quantity added before coating was at a lower level than the normal quantity necessary to get standard keeping properties.
  • a gelatin silver chloro-bromide emulsion was made substantially as described in Procedure B.
  • the emulsion samples, thus obtained, were coated as described in Procedure B.
  • a gelatin silver halide emulsion was prepared as described in Procedure A. Three other samples of the redispersed emulsion were added with an equimolar solution quantity of Compound 4, instead of the thiosulfate solution. They were digested and coated as described before. The results are shown in Table 1.
  • a gelatin silver chloro-bromide emulsion has been prepared as described in Procedure B; three samples of the redispersed emulsion have been added with Compound 4, instead of thiosulfate, in equimolar quantity; three other samples with a + 30% molar quantity of Compound 4 as described before. The results of these nine tests are shown in Table 2.
  • a gelatin silver halide emulsion was prepared as described in Procedure C. Samples of the redispersed emulsion have been prepared: the first semple was added with thiosulfate solution, the second with Compound 1 solution; the third with Compound 2 solution, the fourth with Compound 4 solution, the fifth with Compound 5 solution and the last one with Compound 6 solution. Any product was added in equimolar quantity with respect to the thiosulfate. The samples of these emulsions have been digested for three times as described before and coated as usual.The results are shown in Table 3.
  • a gelatin silver halide emulsion was prepared as described in Procedure B. Samples of the digested emulsion have been added with equimolar solution of the Na 2 S 2 0 3 , Compound 1 and Compound 2 chemical sensitizers. The samples were then digested for three times as described before and coated as usual. The sensitometric results are shown in Table 4.
  • a gelatin silver halide emulsion was prepared as described in Procedure B. Samples of the digested emulsion have been added with equimolar solutions of the Na 2 S 2 0 3 , Compound 1, Compound 2 and Compound 4 chemical sensitizers; each sample has then been digested for three times as described before and coated as usual. The sensitometric results are shown below in Table 5.
  • a gelatin silver halide emulsion was prepared as described in Procedure D. Samples of the digested emulsion were added with equimolar solution of the Na 2 S 2 0 3 and Compound 4 chemical sensitizers, then digested for three times as described before and coated as usual. The sensitometric results are shown below in Table 6.

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
EP19810901016 1980-10-02 1980-10-02 Chemically sensitized silver halide photographic emulsions and color photographic elements containing said emulsions Expired EP0061446B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1980/001402 WO1982001260A1 (en) 1980-10-02 1980-10-02 Chemically sensitized silver halide photographic emulsions and color photographic elements containing said emulsions

Publications (3)

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EP0061446A1 EP0061446A1 (en) 1982-10-06
EP0061446A4 EP0061446A4 (en) 1983-04-18
EP0061446B1 true EP0061446B1 (en) 1985-05-15

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EP19810901016 Expired EP0061446B1 (en) 1980-10-02 1980-10-02 Chemically sensitized silver halide photographic emulsions and color photographic elements containing said emulsions

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EP (1) EP0061446B1 (enrdf_load_stackoverflow)
JP (1) JPS57501495A (enrdf_load_stackoverflow)
DE (1) DE3070661D1 (enrdf_load_stackoverflow)
WO (1) WO1982001260A1 (enrdf_load_stackoverflow)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1678832A (en) * 1927-06-06 1928-07-31 Eastman Kodak Co Photographic light-sensitive material and process of making the same
DE1209425B (de) * 1964-08-08 1966-01-20 Agfa Gevaert Ag Lichtempfindliches photographisches Material mit mindestens einer stabilisierten Halogensilberemulsionsschicht
US3753908A (en) * 1971-08-30 1973-08-21 Chevron Res Oxidation inhibited lubricating oil compositions with extreme pressure properties
JPS5125339B2 (enrdf_load_stackoverflow) * 1972-03-29 1976-07-30
US4116697A (en) * 1976-12-17 1978-09-26 E. I. Du Pont De Nemours And Company Sulfur-substituted isothioureas in silver halide emulsions
JPS5945134B2 (ja) * 1977-11-16 1984-11-05 三菱製紙株式会社 ハロゲン化銀写真乳剤

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WO1982001260A1 (en) 1982-04-15
DE3070661D1 (en) 1985-06-20
EP0061446A1 (en) 1982-10-06
EP0061446A4 (en) 1983-04-18
JPS57501495A (enrdf_load_stackoverflow) 1982-08-19

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