WO1980000040A1 - Compose organique halogene utilise dans des emulsions photographiques de type positifs - Google Patents

Compose organique halogene utilise dans des emulsions photographiques de type positifs Download PDF

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Publication number
WO1980000040A1
WO1980000040A1 PCT/US1979/000378 US7900378W WO8000040A1 WO 1980000040 A1 WO1980000040 A1 WO 1980000040A1 US 7900378 W US7900378 W US 7900378W WO 8000040 A1 WO8000040 A1 WO 8000040A1
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WO
WIPO (PCT)
Prior art keywords
emulsion
organic halogen
halogen compound
silver halide
direct positive
Prior art date
Application number
PCT/US1979/000378
Other languages
English (en)
Inventor
R Prados
Original Assignee
Du Pont
R Prados
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Du Pont, R Prados filed Critical Du Pont
Priority to DE7979900704T priority Critical patent/DE2967425D1/de
Publication of WO1980000040A1 publication Critical patent/WO1980000040A1/fr

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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
    • G03C1/485—Direct positive emulsions
    • G03C1/48515—Direct positive emulsions prefogged
    • G03C1/48523—Direct positive emulsions prefogged characterised by the desensitiser

Definitions

  • This invention relates to the field of photography, and more particularly to direct positive silver halide emulsion technology.
  • the present invention advances beyond the prior art and is directed to a process requiring the addition of certain organic halogen compounds to direct positive silver halide photographic elements, characterized in that the addition step is followed by a digestion step.
  • the term "digestion” is used here to denote a process in which a direct positive silver halide emulsion containing one of the aforesaid organic halogen compounds is heated for a time and at a temperature sufficient to permit the organic halogen compound to selectively oxidize silver fog centers in the emulsion. The result is an increase in the photosensitivity of the emulsion, with no adverse effect on stability.
  • a direct positive silver halide photographic emulsion of superior speed and stability is produced by a process which consists essentially of the steps of (1) preparing a silver halide precipitate in a colloid binder, (2) fogging the resulting emulsion, (3) adding an organic halogen compound, and (4) coating the emulsion on a support, characterized in that, the emulsion is digested after step (3) and before step (4) to promote thermal reaction of the organic halogen compound with the fog centers, whereby the organic halogen compound is reduced and the fog centers are partially oxidized.
  • the present invention provides the means to increase the sensitometric speed response of direct positive silver halide photosensitive elements without undue sacrifice of gradient, top density, and resolution, and without the need for formulation changes.
  • Speed can be increased by a factor of 5 without affecting Dmax or contrast.
  • the degree of speed increase is surprising in comparison to other means of increasing sensitivity, which include: alteration of silver halide grain growth, metal doping of the grains, and the use of new sensitizing and desensitizing dye structures and dye combinations.
  • Halogen substitutions found to be most effective are bromine and chlorine. Iodine compounds have not been shown to be effective, and fluorine compounds represent an unreactive class of compounds.
  • the organic molecule to which the bromine or chlorine is attached must serve as a suitable carrier and not allow premature discharge, decomposition, or volatilization since this would negate the desired enhancement of photosensitivity. For example, new control or environmental protection facilities are often necessitated by the use of compounds of high volatility, but the compounds of the present invention have no such disadvantage.
  • organic halogen compounds which may be characterized as weak oxidizing agents, derive their utility from being reacted in the emulsion during the thermal treatment, i.e., digestion, whereby the weak oxidant is reduced and therefore no further changes in properties occur upon aging. It is as a result of practical limitations imposed by the direct positive 'photosystem that the activity of particularly effective organic halogen compounds must be determined experimentally.
  • Particularly effective compounds of the instant invention are the following: 2-chloro-4-nitrobenzyl chloride, 2,2,3,4-tetrachloronaphth-1-one, 1,4-bis (trichloromethyl)-benzene, tribromoacetic acid, tetrachlor-orthobenzoquinone, 1,3-dibromo-5,5-dimethyl hydantoin, 1-chlorobenzotriazole, ⁇ -bromo-p-toluic acid, 2-trichloromethyl-4 (3H) quinazolinone, p-bromoacetophenone, m-nitrobenzyl chloride, 2-tribromomethylquinaldine, 2,6-dichlorobenzonitrile, 2-tribromomethylquinoline, 2-dibromomethylquinoline, 2- tri bromomethylquinoxaline, and ⁇ , ⁇ , ⁇ ', ⁇ '- tetrabromoxylene.
  • the increase in direct positive photosensitivity provided by the present invention results from the simple step of adding and digesting the organic halogen compound in the emulsion.
  • this technique it is possible to use this technique to obtain desirable speed increase without the necessity of further modification of an existing direct positive emulsion formulation.
  • other techniques for speed increase usually require that other changes and modifications accompany the means for speed increase.
  • to provide a new grain might require alteration of the steps of ripening the emulsion; of washing, sensitizing and stabilizing the emulsion; using auxiliary additives, etc. to allow coating and drying of the emulsion.
  • a new or improved dye may not be compatible with a sensitization technique previously used.
  • the present invention is operative with silver halide grains produced by both single jet and double jet precipitation techniques, to yield heterodisperse and monodisperse grain size distribution.
  • metal ions may be introduced to modify the photographic response and/or to act as fogging agents.
  • Nonmetals, and compounds thereof may also be used to fog or precondition the grains during physical ripening, or, as an alternate fogging mechanism, the grains may be exposed to actinic radiation.
  • the term "core-shell" grain has come to apply to such layered grains.
  • both the type of fogging agent to be used and the degree of fogging are dependent on concentration, pH, pAg, temperature, and duration of the treatment. Both surface and internal fog centers are recognized as functional for direct positive emulsions.
  • Suitable metals for fogging include gold, tin, lead, palladium, and iridium.
  • Suitable nonmetallic compounds include amine borane, hydrazine, thiourea dioxide, formaldehyde, and allyl thiourea.
  • the organic halogen compound may be added to the emulsion, and the oxidation-reduction reaction is carried out by holding the system at an elevated temperature to allow it to proceed towards completion.
  • the organic halogen compounds of this invention will function in the presence of dyes known to be useful in direct positive emulsions, including those disclosed, for example, in U.S. 3,615,643; U.S. 3,583,870; U.S. 3,867,149; U.S. 3,898,216; and U.S. 3,747,986.
  • These dyes are useful as desensitizers which increase the response of direct positive silver halide emulsions. While useful with these desensitizing dyes, the present invention also functions in their absence.
  • Specially sensitizing dyes that are not electron accepting may also be present in the emulsion such as single and complex cyanines, merocyanines, styryls, and hemicyanines.
  • the silver halide constituent of the direct positive silver halide emulsions described herein may consist of pure or mixed silver chloride, bromide, or iodide, and the grains may be regular or irregular in shape, e.g., cubic, octahedral, rhombohedral, etc.
  • the novel emulsions described in copending application Serial No. 972,972 filed December 26, 1978, "Novel Silver Halide Crystals with Two Surface Types", are also useful in the practice of the present invention.
  • speed-increasing compounds such as polyalkylene glycols; surface active agents which are useful as coating aids; antifoggants; and stabilizers, including indazoles, imidazoles, azaindenes, mercury, and polyhydroxy benzene compounds.
  • useful ingredients for these direct positive elements include hardeners, antistatics, matting agents, plasticizers, brighteners, and natural and synthetic wetting agents. All these useful ingredients may be combined to yield formulations capable of being coated on suitable supports such as cellulose nitrate film, cellulose ester film, polyvinyl acetal film, polystyrene film, poly (ethylene terephthalate) film, and related films or resinous materials, as well as glass, paper, metal and the like.
  • EXAMPLE 1 A rhodium-doped monodisperse cubic Ag(I)Br emulsion containing 1.0% iodide and 0.01% rhodium was prepared by the balanced double jet precipitation technique, maintaining a pAg of 8.2. After completion of physical ripening, the emulsion was coagulated with polyvinyl alcohol o-sulfobenzaldehyde acetal and the excess halide salts removed by decanting. The washed emulsion was redispersed in gelatin; the pH was adjusted to 7.5, and the pAg to 8.0.
  • the emulsion was fogged by adding, per mole of silver halide, 2.4 x 10 -7 mole of cesium thiodecaborane and 3.1 x 10 -6 mole of gold chloride stabilized with hydrochloric acid. After digesting at 72°C for 2 hours the emulsion was cooled to 35°C and cetyl betaine was added as a coating aid. The emulsion was split into portions and additions made as in Table 1 below.
  • the samples were coated on photographic grade polyester .base at 35 mg/dm 2 silver bromide.
  • the samples with dye were exposed at 10 -3 sec. with a 19 line compensator on an EGG sensitometer through a ⁇ 2 wedge.
  • the nondyed samples were exposed using a tungsten lamp (G.E. 2F Photo Flood-750 watts) operated at 35 volts. for 15 sec.
  • the samples were developed in a standard metol-hydroquinone developer for one minute, dipped in an acetic acid stop for 30 sec. , fixed in a standard thiosulfate fixer for one minute, and dried.
  • the samples showed the sensitometric response reported in Table 2 where the speed was measured at 0.1 optical density over Dmin and the gradient is measured over the straight line curve portion.
  • Table 2 shows that similar speed increases can be obtained with and without the presence of the direct positive dye. The results also show that the effects of dye and halogen-donating compound are additive.
  • EXAMPLE 2 An emulsion prepared and fogged in the same manner as that in Example 1 was split into two equal portions. To Part VI, 48.5 mg of
  • Example 2 An emulsion prepared as in Example 1 was split into three equal portions. To Part VIII, 1.1 gms of 2-dibromomethylquinoline/mole of silver halide was added. To Part IX 0.12 gms of 2-tribromomethyl quinoline/mole silver halide were added. Part X was kept as a control. The direct positive dye was added and samples coated at a coating weight of 40 mg AgBr/dm 2 . The samples were exposed for one minute through a ⁇ 2 wedge in a contact mode using a K&E Tungsten source at maximum output with a 0.6 neutral density filter. They were then processed in a standard metolhydroquinone developer, put in an acid stop for 30 seconds, and fixed in a thiosulfate fixer for one minute. The results are listed in Table 4.
  • EXAMPLE 4 Emulsion samples were prepared as in Example 1 and split into three portions. To sample XI was added 0.122 mg of 2-tribromomethyl- quinoxaline/mole of silver halide, to sample XII 0.122 mg of 2-tribromomethylquinoline/mole silver halide, and sample XIII was the control. The samples were coated without the direct positive dyes and processed as in Example 1. The results are reported in Table 5, and they show that under similar processing conditions the 2-tribromomethylquinoline and 2-tribromomethyl-quinoxaline compounds behave identically.
  • EXAMPLE 6 An emulsion similar to that of Example 1 but fogged with 2.3 x 10 -7 mole of cesium thiodecaborane and 1.9 x 10 -6 mole of gold chloride/mole of silver halide and without direct positive dye, was used for further comparisons. Saponin was used as a coating aid in place of cetyl betaine. Table 7 gives comparative results.
  • EXAMPLE 7 A monodisperse cubic trihalide emulsion (Br-90/Cl-9.5/I-0.5) was prepared by a balanced double jet precipitation as described in Example 1 of S.N. 972,972. Unlike the iodobromide emulsion of Example 1, no rhodium was included during precipitation. The emulsion was washed and redispersed as in Example 1. The emulsion was fogged by adding thereto 7.3 x 10 —8 moles of cesium thiadecaborane and 1.6 x 10 -4 mole of gold chloride, stabilized with HCl, per mole of silver halide, followed by digesting at 72°C for 100 minutes.
  • Example 8 gives comparative results obtained with the splits of this emulsion with and without the digestion step of the invention. Samples were coated at 35 mg/dm 2 and exposed and processed as in Example 1.
  • this compound Unlike other organic halogen compounds which show an effect on sensitivity even without digestion, this compound requires a longer digestion period than more active halogen oxidizing agents used in previous examples.
  • EXAMPLE 9 An emulsion was prepared as in Example 1 except that the fogging reaction was carried out with 2.9 x 10 -7 mole of cesium thiodecaborane and 4.6 x 10 -6 mole of gold chloride per mole of silver halide. Table 10 gives comparative results obtained when the same amount of an organic halogen compound was digested for different times in comparison to a control containin no addition. 10
  • Temperatures of from 40°C to 80°C are useful for the digestion reaction without adversely affecting the emulsion. Times as short as 5 minutes and up to as long as several hours can be used in order to accommodate the reactivity of the particular organic halogen compound being used to react with the fogged centers.
  • the effective amount of organic halogen compound may vary from as little as 0.01 g to as much as 1.00 g. It has been found convenient to operate with temperature of from 45°C to 65°C for periods of from 10 to 120 minutes using from 0.015 g to 0.50 g of the organic halogen compounds.

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

Abstract

Un compose halogene organique est ajoute a une emulsion photographique d'halogenure d'argent a phototype positif voile, et l'emulsion est digeree avant d'etre appliquee sur un support. On obtient une vitesse et une stabilite accrues. Des quinolines et des quinoxalines bromees sont particulierement efficaces.
PCT/US1979/000378 1978-06-02 1979-06-01 Compose organique halogene utilise dans des emulsions photographiques de type positifs WO1980000040A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE7979900704T DE2967425D1 (en) 1978-06-02 1979-06-01 Organic halogen compounds used in direct positive emulsions

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US91201678A 1978-06-02 1978-06-02
US912016 1986-09-26

Publications (1)

Publication Number Publication Date
WO1980000040A1 true WO1980000040A1 (fr) 1980-01-10

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PCT/US1979/000378 WO1980000040A1 (fr) 1978-06-02 1979-06-01 Compose organique halogene utilise dans des emulsions photographiques de type positifs

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EP (1) EP0016061B1 (fr)
JP (1) JPS6161372B2 (fr)
BE (1) BE876734A (fr)
CA (1) CA1142788A (fr)
DE (1) DE2967425D1 (fr)
WO (1) WO1980000040A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0341728A2 (fr) * 1988-05-13 1989-11-15 Fuji Photo Film Co., Ltd. Matériaux photographiques à l'halogénure d'argent

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4845011A (en) * 1987-10-23 1989-07-04 Hoechst Celanese Corporation Visible light photoinitiation compositions
US4945027A (en) * 1987-10-23 1990-07-31 Hoechst Celanese Corporation 1,4 or 9,10 dimethoxyanthracene triggers for 2-tri(chloro or bromo)methyl-4(1H)-quinazolimone polymerization initiators
JPH0271172U (fr) * 1988-11-16 1990-05-30
GB9221383D0 (en) * 1992-10-12 1992-11-25 Minnesota Mining & Mfg Photothermographic imaging materials and antifoggants therefor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB957192A (en) * 1959-10-15 1964-05-06 Agfa Ag A method and material for the production of photographic images
US3495987A (en) * 1965-09-03 1970-02-17 Du Pont Photopolymerizable products
US3531290A (en) * 1966-03-11 1970-09-29 Eastman Kodak Co Direct positive silver halide emulsions containing excess halide
US3632340A (en) * 1968-09-09 1972-01-04 Eastman Kodak Co Cored direct positive silver halide emulsion developed with polyhydroxybenzene
US3637387A (en) * 1967-10-24 1972-01-25 Agfa Gevaert Nv Direct positive emulsion containing a halide releasing compound developed in the presence of an unsubstituted hydrazine
US3708297A (en) * 1969-10-09 1973-01-02 Agfa Gevaert Stabilizing with iodide an imagewise exposed photosensitive composition containing a halogenated photoactivator and an organic amine color former
US3957518A (en) * 1972-07-13 1976-05-18 Agfa-Gevaert N.V. Direct-positive silver halide emulsions

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1597598A1 (de) * 1966-11-16 1970-06-25 Gaf Corp Gelatine fuer photographische Zwecke

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB957192A (en) * 1959-10-15 1964-05-06 Agfa Ag A method and material for the production of photographic images
US3495987A (en) * 1965-09-03 1970-02-17 Du Pont Photopolymerizable products
US3531290A (en) * 1966-03-11 1970-09-29 Eastman Kodak Co Direct positive silver halide emulsions containing excess halide
US3637387A (en) * 1967-10-24 1972-01-25 Agfa Gevaert Nv Direct positive emulsion containing a halide releasing compound developed in the presence of an unsubstituted hydrazine
US3632340A (en) * 1968-09-09 1972-01-04 Eastman Kodak Co Cored direct positive silver halide emulsion developed with polyhydroxybenzene
US3708297A (en) * 1969-10-09 1973-01-02 Agfa Gevaert Stabilizing with iodide an imagewise exposed photosensitive composition containing a halogenated photoactivator and an organic amine color former
US3957518A (en) * 1972-07-13 1976-05-18 Agfa-Gevaert N.V. Direct-positive silver halide emulsions

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0341728A2 (fr) * 1988-05-13 1989-11-15 Fuji Photo Film Co., Ltd. Matériaux photographiques à l'halogénure d'argent
EP0341728A3 (fr) * 1988-05-13 1991-02-06 Fuji Photo Film Co., Ltd. Matériaux photographiques à l'halogénure d'argent
US5061615A (en) * 1988-05-13 1991-10-29 Fuji Photo Film Co., Ltd. Silver halide photographic materials

Also Published As

Publication number Publication date
EP0016061B1 (fr) 1985-04-10
JPS6161372B2 (fr) 1986-12-25
JPS55500380A (fr) 1980-06-26
EP0016061A4 (fr) 1981-08-27
CA1142788A (fr) 1983-03-15
BE876734A (fr) 1979-12-03
EP0016061A1 (fr) 1980-10-01
DE2967425D1 (en) 1985-05-15

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