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
  • G03C1/34—Fog-inhibitors; Stabilisers; Agents inhibiting latent image regression
  • G03C1/346—Organic derivatives of bivalent sulfur, selenium or tellurium
• • 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 sensitivity of a photographic emulsion can be affected in two ways.
• the sensitivity can be increased in the course of preparation of the emulsion at the stage of so-called chemical ripening, by increasing the ripening time or by adding suitable substances such as thiosulfate or other compounds which usually contain sulfur.
• the other method of increasing the sensitivity of a'photographic emulsion consists of adding so-called development accelerators or chemical sensitizers. These are usually added to the completely ripened emulsion.
• Development accelerators which have been described for this purpose are, for example, compounds which have an onium structure (such as quaternary ammonium and pliosphonium salts and ternary sulfonium salts) and also polyalkylene oxides and derivatives thereof are very frequently employed.
• onium structure such as quaternary ammonium and pliosphonium salts and ternary sulfonium salts
• polyalkylene oxides and derivatives thereof are very frequently employed.
• R an alkyl radical having up to six carbon atoms; two R radicals attached to the same N atom may be conjoined so as to form together with the N atom a saturated 5-, 6- or 7-membered heterocyclic ring, which may also contain further hetero atoms, such as for example piperidine, morpholine, thiomorpholine, piperazine, pyrrolidine, hexamethyleneimine, or an unsaturated heterocyclic ring such as pyridine; in the latter case R is not present; R on alkyl radical having up to six carbon atoms which may be substituted, for example, a hydroxyalkyl, cyanoalkyl, haloalkyl or carboxyalkyl, an aralkyl radical such as benzyl or phenylethyl; the phenyl radical may be substituted (e.g., by chlorine, Nl-l OH, alkyl or other substituents); n an integer of from 1 to 6; and X
• Tim/Q 'GHZQ CaHs C211 XXI The preparation of the compounds to be used according to the invention is carried out in a known manner.
• a dialkylaminoalkyl mercaptan prepared via an isothiouronium salt may be oxidized with suitable agents to form bis-(dialkylaminoalkyl)-disulfide which then may be quaternized in some suitable manner.
• the disulfides required for quaternization can also be obtained conveniently from dialkylaminoalkyl chlorides via the alkali metal salts of w-thiosulfato-N,N-dialkylamino-alkanes.
• BlS-(DIMETHYLAMINOPROPYL)-DlSULFlDE 158 g. (1 mol) of 'y-chloropropyl-dimethylamino hydrobromide are dissolved in 500 ml. of methanol.
• a solution of 158 g. (1 mol) of anhydrous sodium thiosulfate in 500 ml. of water are added dropwise with stirring to the boiling methanolic solution.
• a solution of 112 g. of iodine (0.88 mol) in 500 to lOOO ml. of methanol is then added slowly in the course of 2 to 3 hours to the boiling reaction solution. The solution is then concentrated by evaporation.
• the other compounds can be prepared in a similar manner.
• Some other methods for preparing bis-dialkylaminoalkyldisultides and their quaternary salts are given in Archiv der Pharmazie 293, (1960) pp. 55-67 and in .l.Org.Chem. 32, (1967) page 2,985 et seq.
• the compounds according to the invention show their advantageous effect particularly clearly when they are used in place of thiosulfate or other sulfur compounds in chemical ripening.
• the considerable reduction in the fogging in the samples is very striking. This reduction in fogging can be observed not only in fresh samples but also after the samples have been stored in the heating cupboard.
• the effect of the substances according to the invention is, however, not limited to ripening. Similar, although not quite so marked effects can also be observed when using these compounds as casting additives.
• the specific advantage lies not so much in the increase in sensitivity, which can be regarded as only average, but in the combination of increase in sensitivity with reduction in fogging which enables other ingredients, which might possibly increase fogging, to be added to the emulsion without resulting in a net increase in fogging.
• Emulsions prepared with the compounds according to the invention will, therefore, be particularly suitable for combining with other development accelerators.
• the reduction in fogging will also be very important for the preparation of color emulsions, since these are normally very susceptible to fogging.
• US. Pat. No. 2,521,926 discloses the use of bis-(ydiethylaminopropyl)-disulfide as a ripening agent. Only one disulfide compound is described in the said patent, and it is stated there that its ripening action is different from that of the normal sulfur ripening agents. In the following examples, the hydrochloride of this compound and a few other diaminodisulfides have been given for comparison. From the experiments it will be seen that the effect according to the invention is confined to the quaternary salts, and that the effect is not achieved by bis-(dialkylaminoalkyl)-disulfides and their salts, which are not quaternized.
• the substances according to the invention may be added to the photographic emulsion at any stage of its preparation, i.e., during or after chemical ripening. They may also be added to the casting solution directly before casting. The quantity added depends on the effect required, and can be determined by those skilled in the art at any time by the usual tests.
• the inventive compounds per mol of silver halide. Concentrations of between 0.03 and 0.6 g. per mol of silver halide are preferred. If the substances according to the invention are added to the casting solution of the finished emulsion, the quantities required are generally slightly higher. They are then between 0.005 and 20 g., preferably between 0.003 and 6 g. per mol of silver halide.
• the substances according to the invention may be used in any silver halide emulsions.
• Suitable silver halides are silver chloride, silver bromide or mixtures thereof, optionally with a small silver iodide content of up to 10 mols percent.
• the silver halides may be dispersed in the usual hydrophilic compounds such as carboxymethylcellulose, polyvinyl alcohol, polyvinyl pyrrolidone, alginic acid and its salts, esters or amides and preferably gelatin.
• the emulsions may also contain other chemical sensitizers, e.g., quaternary ammonium and phosphonium salts and ternary sulfonium salts, reducing agents such as stannous salts, polyamines such as diethylene triamine, or sulfur compounds as described in U.S. Pat. No. 1,574,944.
• the given emulsions may also contain salts of noble metals such as ruthenium, rhodium, palladium, iridium, platinum, or gold for chemical sensitization, as described in the article by R. Koslowsky, Z.Wiss.Phot. 46, 65-72(1951).
• the emulsions may also be optically sensitized, e.g., with the usual polymethine dyes such as merocyanines, basic or acid carbocyanines, rhodacyanines, hemicyanines, styryl dyes, or oxonoles. Sensitizers of this type have been described by F.M. Hamer in the book The Cyanine Dyes and related Compounds (1964).
• the emulsions may contain the usual stabilizers, such as homopolar or salt type compounds of mercury with aromatic or heterocyclic rings, (for example mercapto triazoles), simple mercury salts, sulfonium mercury double salts and other mercury compounds.
• stabilizers such as homopolar or salt type compounds of mercury with aromatic or heterocyclic rings, (for example mercapto triazoles), simple mercury salts, sulfonium mercury double salts and other mercury compounds.
• Azaindenes preferably tetra or pentaazaindenes, particularly those which are substituted with hydroxyl or amino groups, are also suitable as stabilizers. Such compounds have been described in the article by Birr, Z.Wiss.Phot. 47, 2-58 (1952).
• Other suitable stabilizers are heterocyclic mercapto compounds, e.g., phenylmercaptotetrazole, quaternary benzothiazole derivatives, and benzotriazole.
• the emulsions may be hardened in the usual manner, for example with formaldehyde or halogen substituted aldehydes which contain a carboxyl group, such as mucobromic acid, diketones, methanesulfonic acid esters, and dialdehydes.
• formaldehyde or halogen substituted aldehydes which contain a carboxyl group, such as mucobromic acid, diketones, methanesulfonic acid esters, and dialdehydes.
• the emulsions treated with the quaternary salts which contain a disulfide linkage, according to the invention may also contain color-forming couplers for the production of color photographic images.
• Sample A Comparison sample-without additive Sample B: 7 mg. of Compound 1V Sample C: 7 mg. of Compound 1X Sample D: 4 mg. of Compound X11 Sample E: 4 mg. of Compound XXII Sample F: 4 mg. of Compound 11 Sample G: 4 mg. of Compound XlV Sample 1-1: 4 mg. of Compound X1 Sample I: 4 mg. of Compound X111 Sample K: 4 mg. of Compound 111 Sample L: 4 mg. of Compound XV The afterripening is carried out to maximum sensitivity and the samples are made ready for casting by the addition of 600 mg. of saponin as wetting agent, 200 mg.
• a difference of 3.0 represents a difference of one shutter stop.
• EXAMPLE 2 An emulsion as described in Example 1 is divided into eight equal parts and the following compounds are added to the individual parts which are then ripened to maximum sensitivity: Sample A: Comparison samplewithout additive Sample B: 4 mg. of Compound 1 Sample C: 4 mg. of Compound V11 Sample D: 4 mg. of Compound X Sample E: 4 mg. of Compound X1 Sample F: 7 mg. of Compound XVI Sample G: 4mg. of Compound XlX Sample 1-1: 4 mg. of Compound XXI The samples are prepared for casting and developed as in Example 1.
• a difference of 3.0 represents a difference of one shutter stop.
• EXAMPLE 3 An emulsion as described in Example 1 is divided into 6 equal parts and the following compounds are added to the individual parts which are then ripened to maximum sensitivity.
• Sample A Comparison samplewithut additive
• Sample B 4 mg. of a compound of the formula CgH - ZHCI (according to US. Pat. No. 2,521,926)
• Sample C 7 mg. of a compound of the formula
• Sample D 4 mg. of Compound 1X
• the samples are prepared for casting and developing as in Example 1.
• Sample F 60 mg. of a compound of the formula 1 5 for comparison
• Sample G 60 mg. of a compound of the formula H C ⁇ 02115 N-CHzCH CH -S-S-CH;CHOH -N for comparison
• the casting solutions obtained were cast on a film support; they were exposed in a sensitometer behind a grey step wedge and developed for 6 minutes in a developer of the following composition:
• a difference of 3.0 represents a difference of one shutter stop.
• EXAMPLE 5 An emulsion as described in Example 4 was divided into four equal parts and the following compounds were added to the individual parts (base on 1 kg. of emulsion):
• Sample A Comparison samplewithout additive
• Sample B 100 mg. of Compound V11
• Sample C 100 mg. of Compound IV
• Sample D mg. ofCompound V The casting solutions obtained were cast and developed as in Example 4.
• a light-sensitive photographic material having at least one silver halide emulsion layer, characterized in that it contains a sensitizing amount of a compound of the following formula:
• R an alkyl radical having up to six carbon atoms; two R radicals attached to the same nitrogen atom may, with this nitrogen atom, form a 5-, 6- or 7-membered ring containing at least one hetero atom;
• R an alkyl radical having up to six carbon atoms, or an aralkyl radical
• n an integer of from 1 to 6;
• X is absent when R contains a carboxylate group.
• a light-sensitive photographic material according to claim I wherein the silver halide emulsion layer in addition contains color couplers.
• a light-sensitive photographic material according to claim 1 which contains a compound of the following formula:
• a light-sensitive photographic material according to claim 1 which contains a compound of the following formula:
• R an alkyl radical having up to six carbon atoms; two R radicals attached to the same nitrogen atom may, with this nitrogen atom, form a 5-, 6- or 7-membered ring containing at 5 least one hetero atom;
• n an integer of from i to 6;
• X e any anion; X is absent when R contains a carboxylate group.

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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)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (4)

Citations (3)

• 1968
  • 1968-12-23 DE DE19681816572 patent/DE1816572A1/de active Pending
• 1969
  • 1969-12-15 CA CA069827A patent/CA936038A/en not_active Expired
  • 1969-12-17 BE BE743256D patent/BE743256A/xx unknown
  • 1969-12-17 US US886039A patent/US3640715A/en not_active Expired - Lifetime
  • 1969-12-22 CH CH1913769A patent/CH533321A/de not_active IP Right Cessation
  • 1969-12-23 JP JP44103307A patent/JPS4925897B1/ja active Pending
  • 1969-12-23 FR FR6944657A patent/FR2026970A1/fr not_active Withdrawn
  • 1969-12-23 GB GB1264563D patent/GB1264563A/en not_active Expired

Patent Citations (3)

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