Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D253/00—Heterocyclic compounds containing six-membered rings having three nitrogen atoms as the only ring hetero atoms, not provided for by group C07D251/00
  • C07D253/02—Heterocyclic compounds containing six-membered rings having three nitrogen atoms as the only ring hetero atoms, not provided for by group C07D251/00 not condensed with other rings
  • C07D253/06—1,2,4-Triazines
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D253/00—Heterocyclic compounds containing six-membered rings having three nitrogen atoms as the only ring hetero atoms, not provided for by group C07D251/00
  • C07D253/08—Heterocyclic compounds containing six-membered rings having three nitrogen atoms as the only ring hetero atoms, not provided for by group C07D251/00 condensed with carbocyclic rings or ring systems
  • C07D253/10—Condensed 1,2,4-triazines; Hydrogenated condensed 1,2,4-triazines
• • 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
  • G03C1/49—Print-out and photodevelopable emulsions
• • 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
  • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
  • G03C8/24—Photosensitive materials characterised by the image-receiving section
  • G03C8/243—Toners for the silver image

Definitions

• Photographic elements which comprise a radiation-sensitive silver halide emulsion layer of the light developable type.
• the layer is applied from a coating composition containing a silver iodide sol and/or a compound which will release free iodide ions and a halogen acceptor corresponding to the formula or to a tautomeric structure thereof as follows:
• each of R R R R R and R is hydrogen, an alkyl group or an aryl group, with the proviso, however, that at least one of the substituents R and R is hydrogen; R, and R may also be the atoms necessary to complete a carbocylic ring.
• These light-developable silver halide materials are useful in high-speed recording such as high-speed oscillographic recording of events which occur in rapid sequence, and the like.
• the present invention relates to photographic elements comprising an improved light-developable radiation-sensitive silver halide emulsion layer, as well as to a process for making records employing said elements.
• the light-developable silver halide materials have become of increasing interest, for they possess desirable properties for high speed recording, such as high speed oscillographic recording of events, which occur in rapid sequence, and the like.
• Light-developable silver halide materials for direct recording are radiation-sensitive materials in which a visible image can be obtained, after an exposure to a high intensity source of radiation has been initially utilised to form a latent image, by an additional exposure to a radiation of lower intensity such as ditfuse daylight or artificial light.
• the secondary exposure, also called latensification is an overall exposure, including exposing the areas in which the initial latent image was formed as well as the surrounding background to an additional amount of radiation.
• each of R R R R and R represents a hydrogen atom, an alkyl group including a substituted alkyl group or an aryl group including a substituted aryl group, with the proviso, however, that at least one of the substituents R and R represents a hydrogen atom;
• R and R may also represent the atoms necessary to complete a carbocyclic ring including a substituted carbocyclic ring, to light-developable radiation-sensitive silver halide emulsions results unexpectedly and surprisingly in the production of a light-developable material in which an improved image can be obtained, showing a favourable contrast between the image and the background (i.e.
• the effect of the simultaneous addition of the above compounds is much more important than the effects obtained on the one hand by the addition of the halogen acceptor alone and on the other hand by the addition of the silver iodide sol and/ or the compound splitting off iodide ions alone.
• the difierence between the maximum and minimum density is considerably lower than when both groups are present together.
• the improved light developable radiation sensitive photographic silver halide elements according to the pres ent invention permit a rapid access to and prolonged examination of the image formed on photodevelopment and also permit a chemical development and fixing treatment in order to obtain permanent records of the traces or images.
• the material according to the present invention shows a high degree of sensitivity to the trace beam coupled with a highly stable background i.e. a background which is not very sensitive to low intensity radiation, thus resulting in a maximum contrast between the image and background.
• the images or traces obtained on lightdevelopment with elements according to the present invention are characterized by a high net density, i.e.
• Another advantage offered by the hght'developable 4-methyl-3-thio-1,2,4-triazfospiro[5,5]undecane-35-dione :lements of the invention is that it is possible to carry out a he light-development while supplying heat, whereby the Melnng o 210 Tjhls compound F be P ecorded image becomes almost immediately visible for pared accofdlng to Pfoparatlon as descl'lbed further he reason that, when heating, it is possible to increase the hereinafteright-intensity of the secondary exposure without produe- ComP 5 ng fog.
• a probable explanation of this phenomenon has 0,11, een given by Jacobs, Phot. Sci.
• This compound can be prepared k according to Preparation 4 as described further herein- 3-thio-1,2,4-triazaspiro['5,5]undecane-3,5-dione after' PREPARATION 1 Melting 224 Preparation descnbed by Fusco A. Preparation of the intermediate product 1-(1'-cyano- 1nd ROSSI, GaZz. Chlm- Ital.
• PREPARATION 2 A Preparation of the intermediate product 1-(1'-cyanocyclohexyl) -4-methy1-thio semicarbazide 105 g. of 4-methyl-thiosemicarbazide are dissolved in 400 ccs. of a mixture of ethanol and water (1 :1). Whilst stirring the solution at C. there are successively added: 57.5 ccs. of acetic acid, a solution of 65 g. of potassium cyanide in 125 ccs. of water and 98 g. of cyclohexanone. The reaction mixture is refluxed for 2 hours, whilst stirring. After cooling, the crystals formed are filtered by suction and washed with ethanol and ether.
• PREPARATION 3 70 g. of 1-phenyl-l-ethoxyacetyl-hydrazine hydrochloride are dissolved in 450 ccs. of water. By adding 17.1 g. of ammonium carbonate 1 aq., the base is set free from its hydrochloride whereupon it is extracted with ether. After drying the etheric solution over molecular sieves, a
• PREPARATION 4 45 g. of l-methyl-l-ethoxyacetyl hydrazine hydrochloride are suspended in 230 ccs. anhydrous ether and whilst thoroughly stirring at 0 C. ammonia gas is introduced. The formed ammonium chloride is removed by filtration. By evaporation of the ether of the filtrate, an oil is left which is again dissolved in 205 ccs. anhydrous ether and this solution is added to a solution of 21.6 ccs. of ethylisothiocyanate in 205 ccs. of anhydrous ether. After stirring for half an hour at room temperature, the ether is evaporated. The residue is dissolved in ccs.
• the amount of halogen acceptor according to the above general formula that is incorporated into the silver halide emulsion layer according to the present in- 'vention may vary within very wide limits viz from about 0.01 g. to about 20 g. per mole of silver halide, but is preferably comprised between about 0.1 g. and about 5 g. per mole of silver halide.
• the halogen acceptor corresponding to the above general formula may also be applied together with other halogen acceptors.
• Very good results have been obtained when using in combination with the halogen acceptors of the present invention the halogen acceptors described in our co-pending applications entitled Light-Developable Photographic Material and Recording Process and Improved Light-Developable Photographic Material and Recording Process, both filed on even date herewith.
• Suitable compounds setting free iodide ions are among others inorganic and organic iodides, organic compounds with labile iodine atom and onium chloroiodates.
• Suitable inorganic iodides are for instance the following water-soluble iodides: calcium iodide, ammonium iodide, lithium iodide, magnesium iodide, potassium iodide and sodium iodide.
• Suitable organic iodides are for instance the iodides having the following structural formulae:
• a silver iodide sol comprising an appropriate protective colloid can be added with the same effect to :he silver halide emulsion.
• a very suitable silver iodide sol can be prepared by slowly adding while strongly rtirring the following solution A to the following solu- :ion B, both solutions being heated to 35 C.
• the amount of compound setting free iodide ions may also vary within very wide limits. In general an amount rom about 0.01 g. to about 20 g. preferably from about ).1 g. to about 5 g. per mole of silver halide is applied. lhe same applies to the limits within which the silver odide sol is used. In the latter case the above amounts -elate to the silver iodide and not to the total sol. The lddition of a member selected from a. silver iodide sol and at least one compound setting free iodide ions, and
• any other addition can occur from a solution of the compound involved in a suitable slvent, which is mostly water but may also be an organic solvent.
• silver iodide is produced on the surface of the silver halid grains of the emulsion, in the former case by conversion and in the latter by adsorption.
• the formation of silver iodide at the surface of the grains and the favourable effects resulting therefrom for the method of the present invention can also be attained by conducting the emulsion layer obtained after coating through a solution, preferably an aqueous solution of a compound setting free iodide ions, or by treating this emulsion layer in some other way therewith.
• any silver halide emulsion of the light-developable type may be used.
• These kinds of emulsions are very well known to those skilled in the art. They mainly or entirely form an internal latent image and only to a little extent an external latent image.
• a silver halide emulsion that mainly or entirely forms an internal latent image and only to a little extent an external latent image is an emulsion in which only few or no exposed grains at all are developable into silver by a developing solution that cannot act as a developer for a latent image inside the grains i.e. a so-called surface develop-er, such as:
• a developing solution that acts as a developer for latent image inside the grains i.e. a so-called internal developer such as the following solution:
• a silver halide emulsion that mainly forms internal latent image and little external latent image there is more particularly meant a silver halide emulsion, a test layer of which upon exposure to a light intensity scale for a fixed time between A00 and 1 sec. and development for 3 min. at 20 C. in the above internal developer, exhibits a maximum density at least 5 times the maximum density obtained when an identical test layer of the said silver halide emulsion is equally exposed and then developed for 4 min. at 20 C. in the above surface developer.
• Silver halide emulsions that meet the above requirement and hence are suitable for being employed in the process of the invention are generally not or only slightly chemically ripened silver halide emulsions, since the extent of the surface latent image-forming capability increases with the degree of chemical ripening.
• Silver chlorobromide and silver bromide emulsions have proved to be specially suitable for the purpose of the invention.
• these emulsions comprise minor amounts of silver iodide, preferably not more than 5 mole percent relative to the total amount of silver halide, they are just as Well suitable.
• the silver halide emulsions for use in the present process are generally gelatin silver halide emulsions.
• the gelatin may wholly or partially be replaced for instance by another protein, a hydrophilic not proteinaceous colloid or a synthetic polymeric substance applied from an aqueous dispersion.
• the light-sensitive silver halide emulsions may be prepared according to all known and conventional techniques for emulsion preparation.
• a method according to which emulsions are prepared, and which has proved to be particularly suitable for the purpose of the invention, is the so-called conversion method according to which an emulsion of a silver salt that has a higher degree of solubility than silver bromide is converted into a silver chlorobromide or a silver bromide emulsion that occasionally contains small amounts of silver iodide. This conversion is carried out preferably very slowly for instance by several consecutive steps.
• emulsions can, if desired, be modified prior to coating by the addition of all kinds of ingredients, which are generally known in the art of emulsion preparation and some of which will be set out specifically hereinafter.
• the common additives for light-sensitive silver halide material such as hardening agents e.g. formaldehyde, coating aids, e.g. saponine, plasticizers, e.g. glycerol, optical sensitisers of the class of the cyanine dyes, the merocyanine dyes, etc., development accelerators, compounds that render the material more resistant to wrinkling and less brittle etc.
• hardening agents e.g. formaldehyde
• coating aids e.g. saponine
• plasticizers e.g. glycerol
• optical sensitisers of the class of the cyanine dyes the merocyanine dyes, etc.
• development accelerators compounds that render the material more resistant to wrinkling and less brittle etc.
• Thiocyanates such as potassium thiocyanate, which further stabilise the light-developed image
• cadmium salts Compounds or mixtures of compounds reducing the background density on latensification e.g. lead salts, and prreferably cadmium salts; these salts are preferably salts that are water-soluble such as lead acetate, lead iodide, lead nitrate, cadmium iodide, cadmium chloride, cadmium bromide, cadmium nitrate, etc.; they give rise to a decrease of the minimum density without, however, decreasing the maximum density to the same extent so that as a result thereof the contrast is enhanced.
• lead salts e.g. lead salts, and prreferably cadmium salts
• these salts are preferably salts that are water-soluble such as lead acetate, lead iodide, lead nitrate, cadmium iodide, cadmium chloride, cadmium bromide, cadmium nitrate, etc.; they give rise to a decrease
• Said salts may be added to the emulsion during the emulsion preparation or the conversion of the silver salt emulsion by means of a bromide as well as just before coating the emulsion on a support. They are added in amounts varying from about 1 g. to about 20 g., preferably from about 5 g. to about g. per mole of silver halide.
• the amount of gelatin applied in emulsion making is preferably such that per kg. of emulsion ready for coating from about g. to about 150 g. of gelatin is present.
• the amount of silver nitrate used in emulsion making preferably varies from about 50 to about 200 g. per kg. of emulsion.
• the emulsion is generally coated in such a way that 1 kg. of emulsion covers approximately from about 20 to about 30 sq. m. of support.
• Suitable support for the elements of this invention include the flexible supports used in the prior art for lightwriting and oscillographic recording. They may be any type of paper, as well as films of cellulose nitrate, cellulose acetate, poly(vinyl acetal), polystyrene, po1y(ethylene terephthalate) and other synthetic resins. Supports of glass, metal, and other substances are not excluded. In this connection conventional photographic base papers may be conveniently utilised.
• said elements are first exposed to a high-intensity actinic radiation e.g. from Xenon tubes, U.V.-lamps or high-pressure mercury arc lamps as used in certain oscillographs.
• a high-intensity actinic radiation e.g. from Xenon tubes, U.V.-lamps or high-pressure mercury arc lamps as used in certain oscillographs.
• the high-intensity radiation source used for the initial or first exposure of the light-developable material is generally rich in blue and ultraviolet radiation but said radiation may be any light or other electromagnetic radiation of either visible or invisible wave lengths, X-rays, gamma rays or an electron beam.
• the material may be light-developed by exposure to low intensity daylight, incandescent light or fluorescent light, or by the use of photoflood lamps as commonly used in photography.
• This secondary exposure must not necessarily be performed with the aid of an actinic radiation source.
• the sharpness of the recorded trace or image may be further increased by a short preliminary exposure of the light-developable radiation-sensitive material according to the invention to ordinary light e.g. daylight, prior to exposing the material to the high-intensity radiation. Indeed, by this short preliminary exposure the gradation in the toe of the characteristic curve and the contrast or net density of the recorded trace or image are increased.
• the material may be chemically developed and fixed before, during or after the photo-development, latensification, or secondary exposure.
• This development is of the internal type which means that it takes place in the presence of an energetic silver halide solubilising agent, e.g. sodium thiosulphate, which is mostly present in the developer itself.
• Said chemical development advantageously occurs in the presence of an anti-fogging agent.
• the halogen acceptor used can function as such at least when it possesses good antifogging properties.
• the antifogging agent may be incorporated in at least one of the composing layers of the photographic element used and/ or in the developer.
• anti-fogging agents Z-mercapto-ethyl-carbanilate, l-phenyl-Z-tetrazoline-S-thione and 4,5, 6, 7-tetrabromo- 1 H-benzotriazole.
• a light-sensitive photographic silver bromide emulsion of the light-developable type i.e. that mainly forms an internal latent image and only to a little extent an external latent image is prepared by conversion of a silver chloride emulsion into a silver bromide emulsion.
• Said silver bromide emulsion is prepared so that an amount of silver bromide equivalent to g. (0.7 mole) of silver nitrate is present per kg. of emulsion.
• the usual emulsion ingredients and coating aids are incorporated into the emulsion, and in addition thereto an orthochromatic sensitizing agent, and 8 g. of cadmium bromide per kg. of emulsion for reducing the background density.
• the emulsion obtained is divided into many different emulsion samples. To these samples are added the additives accoring to the invention as listed in the table hereinafter.
• the halogen-acceptor is added in an amount of 40 ccs. of a 1% by weight solution in a suitable solvent per kg. of emulsion whereas the compound setting free iodide ions, in this particular case potassium iodide, is added in an amount of 10 ccs. of a 4% by weight aqueous solution per kg. of emulsion.
• All emulsion samples obtained are coated on conventional photographic paper supports such that an amount of silver halide equivalent to 4 g. of silver nitrate is present per sq. m. of light-sensitive material.
• the materials comprising potassium iodide or halogenacceptor alone show less difference between the image and background densities than the materials comprising both potassium iodide and halogen-acceptor; thus the contrast between image and non-image areas is enhanced.
• EXAMPLE 2 A light-sensitive photographic silver bromide emulsion of the light-developable type is prepared as described in Example 1. The emulsion obtained is now divided into 3 samples A, B and C. To emulsion samples B and C is added per kg. of emulsion as anti-fogging agent 5 ccs. and ccs. respectively of a 5% by weight solution in ethanol of 1-phenyl-2-tetrazoline-5-thione. To sample A no antifogging agent is added.
• each emulsion sample on a conventional photographic paper support 10 ccs. of a 2.5% by weight solution of 6,6 dimethyl-3-thio-1,6-dihydro-as-triazine-3,5-(2H,4H)- dione in ethylene glycol monomethyl ether and 10 ccs. of a 4% by weight aqueous solution of potassium iodide are added per kg. of emulsion.
• Each of the 3 materials obtained is exposed to high intensity-radiation as described in Example 1, and photodeveloped by exposure for min. to ordinary office fluorescent light with a total light intensity of 240 Lux.
• the samples are then fixed, rinsed and dried in the usual way.
• EXAMPLE 3 4 light-sensitive photographic silver bromide materials of the light-developable type are prepared as described in Example 1, however, without cadmium bromide and with additives according to the invention as listed in the table hereinafter. The mentioned concentrations of these additives are per kg. of emulsion ready for being coated.
• each of R R R R and R is hydrogen, an alkyl group or an aryl group, with the proviso, however, that at least one of the substituents R and R is hydrogen; R and R may also be the atoms necessary to complete a carbocyclic ring.
• Photographic element according to claim 2 wherein said water-soluble inorganic iodide is potassium iodide.
• Photographic element according to claim 1 wherein the halogen-acceptor corresponding to the general formula:
• each of R R R R and R is hydrogen, an alkyl group or an aryl group, with the proviso, however,
• R and R may also be the atoms necessary to complete a carbocyclic ring, is present in an amount of from 0.1 to 5 g. per mole of silver halide.
• Photographic element according to claim 9 wherein said thiocyanate is potassium thiocyanate.
• Photographic element according to claim 11, wherein said anti-fogging agent is 1-phenyl-2-tetrazoline-5- thione.
• Photographic element according to claim 1 wherein the member selected from a silver iodide sol and a compound setting free iodide ions is added to the radiationsensitive coating composition just before coating.
• Photographic element according to claim 1 wherein the halogen-acceptor corresponding to the general formula:
• each of R R R R R and R is hydrogen, an alkyl group or an aryl group, with the proviso, however, that at least one of the substituents R and R is hydrogen; R and R may also be the atoms necessary to complete a carbocyclic ring, is added to the radiation-sensitive coating composition just before coating.
• Photographic element comprising a radiationsensitive silver halide emulsion layer of the lightdevelopable type, the silver halide grains of which contain silver iodide at their surface, wherein said emulsion layer contains at least one halogen-acceptor corresponding to the following general formula or to a tautomeric structure thereof:
• Process for recording traces or images comprising exposing to a high intensity actinic radiation a photographic element according to claim 1, and light-developing the latent image formed by said initial exposure by overall exposing said element to a radiation of lower intensity.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Color Printing (AREA)

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Citations (3)

• 1965
  • 1965-10-11 GB GB42969/65A patent/GB1160955A/en not_active Expired
• 1966
  • 1966-10-10 DE DE19661522401 patent/DE1522401A1/de active Pending
  • 1966-10-11 DE DE19661522403 patent/DE1522403A1/de active Pending
  • 1966-10-11 FR FR79931A patent/FR1496596A/fr not_active Expired
  • 1966-10-11 NL NL6614290A patent/NL6614290A/xx unknown
  • 1966-10-11 BE BE688068D patent/BE688068A/xx unknown
  • 1966-10-11 BE BE688065D patent/BE688065A/xx unknown
  • 1966-10-11 US US585731A patent/US3502471A/en not_active Expired - Lifetime
  • 1966-10-11 US US585734A patent/US3431108A/en not_active Expired - Lifetime
  • 1966-10-27 NL NL6615205A patent/NL6615205A/xx unknown

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