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
  • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
  • G03C8/02—Photosensitive materials characterised by the image-forming section
  • G03C8/08—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds
  • G03C8/10—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds of dyes or their precursors
  • G03C8/12—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds of dyes or their precursors characterised by the releasing mechanism
  • G03C8/14—Oxidation of the chromogenic substances
  • G03C8/16—Oxidation of the chromogenic substances initially diffusible in alkaline environment
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/142—Dye mordant

Definitions

• the present invention is concerned with photography and, more particularly, with color diifusion-transfer processess.
• One object of the present invention is to provide processes for improving the density of transfer images which are produced by diffusion-transfer processes utilizing dye developers.
• Another object of the invention is to provide processes for improving the color separation and highlights of multicolor transfer images produced by difiusiontransfer processes utilizing dye developers.
• the invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope for the application of which will be indicated in the claims.
• a photosensitive element containing a silver halide emulsion is exposed and wetted by a liquid processing composition, for example, by immersing, coating, spraying, flowing, etc., in the dark and the exposed photosensitive element is superposed prior to, during, or after Wetting, on a sheetlike support element which may be utilized as an image-receiving element.
• the photosensitive element contains a layer of dye developer and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensitive element is brought into superposed relationship with an image-receiving element. It is also contemplated to utilize the dye developer in the liquid processing composition where monochromatic images are desired.
• the liquid processing composition permeates the emulsion to initiate development of the latent image contained therein.
• the dye developer is immobilized or precipitated in exposed areas as a consequence of the development of the latent image. This immobilization i apparently, at least in part, due to a decrease in the solubility of the dye developer upon oxidation.
• the dye developer is at least partly unreacted, and thus provides an imagewise distribution of unoxidized dye developer, dissolved in the liquid processing composition,
• Multicolored transfer images may be produced through various methods 'by using at least two differentially sensitized silver halide emulsions and developing each emulsion in the presence of a differently colored dye dveloper.
• One method comprises using integral photosensitive elements and processes such, for example, as those claimed and disclosed in the copending U.S. application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed with a single processing solution and transferred to a common image-receiving layer.
• a suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a green-sensitive silver halide emulsion stratum, and -a blue-sensitive silver halide emulsion stratum, each of said emulsions having associated therewith, respectively, a cyan dye developer, n magenta dye developer, and a yellow dye developer.
• the dye developer is disposed in a separate alkali-permeable layer, preferably behind the photosensitive silver halide emulsion with which it is associated.
• the processes of the present invention are especially useful in processing these integral multilayer photosensitive elements.
• the density of highlights of the transfer images produced by such dye developer processes may be substantially improved by carrying out the development in the presence of at least one onium compound and especially in the presence of at least one onium compound selected from the group consisting of quaternary ammonium, quaternary phosphonium, and tertiary sulfonium compounds.
• Onium compounds have been used in the photographic art for quite some time.
• U.S. Patent No. 2,648,604 discloses the use of non-surface-aotive quaternary ammonium compounds as development accelerators
• U.S. Patents Nos. 2,271,623, 2,271,622 and 2,275,727 disclose the use of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds as sensitizers for silver halide emulsions.
• the results and especially the increase in density ob tained by using onium compounds in conjunction with the dye developers in the diffusion-transfer processes of this invention are worthy of note.
• the increase in density in the present processes is not the result of improved surface activity due to the onium compounds because, as will be hereinafter shown, the onium compounds which usually bring about the greatest improvement in density would not be generally classified as surface active. It is believed that the increase in density is at least due in part to the ability of the onium compounds to increase the solubility of the dye developers.
• quaternary ammonium compounds are organic compounds containing a pentavalent nitrogen atom. Generally they can be considered as derivatives of ammonium compounds wherein the four valences usually occupied by the hydrogen atoms are occupied by organic radicals.
• each of the four valences is attached to separate organic radicals, e.g., tetraalkyl quaternary ammonium compounds.
• organic radicals e.g., tetraalkyl quaternary ammonium compounds.
• quaternary ammonium compounds mention may be made of those represented by the following formulae:
• each R is an organic radical
• Y is an anion, e.g.,
• each R is an organic radical, e.g., alkyl, aralkyl, aryl, etc. groups
• X is an anion, e.g., hydroxy, bromide, chloride, toluene sulfonate, etc.
• tertiary sulfonium and quaternary phosphonium compounds mention may be made of lauryldimethylsulfonium p-toluene sulfonate, nonyl-dimethylsulfonium ptoluene sulfonate and octyldimethylsulfonium p-toluene sulfonate, butyldimethylsulfonium bromide, triethylsulfonium bromide, tetraethylphosphonium bromide.
• the onium compounds may be used as the free base or as the salt.
• the anion may be a derivative of any acid.
• the anion is iodide, such iodide may have deleterious effects on the emulsion and suitable precautions should be taken.
• the onium compounds were employed as the bromide.
• onium compounds, which have an anion other than bromide it has been found advantageous in certain instances to add a small amount of potassium bromide.
• the effect of the onium compounds on the density and highlights will vary with the molecular size of the particular onium cation employed. Usually the increase in density will be especially marked as the molecular size of the onium cation decreases. Conversely, the cleanness of the highlights will be especially noticeable with increasing molecular size. Onium cations of intermediate molecular size may provide an especially marked improvement in both the density and highlights. Generally, the cation of the onium compounds which will especially promote increased density, will be devoid of hydrophobic chains having, for example, more than 3 carbon atoms.
• l-ethylpyridinium p-toluene sulfonate l-propyl-pyridinium p-toluene sulfonate, N-phenyl-N,N,N-trimethylammonium p-toluene sulfonate, l-propylpyridinium bromide, 1-ethyl-2- methylpyridinium bromide, l-(fi-hydroxyethyl)-pyridinium bromide, 1-ethyl-2,3-dimethylpyridinium p-toluene sulfonate, 1-ethy1-Z-methoxypyridinium bromide, tetraethylammonium bromide, dimethyldiethylammonium ptoluene sulfonate, 1,1-diethylpiperidinium
• the cation of oniums which will especially promote improved highlights generally will include a hydrophobic chain comprising at least, for example, 4 carbon atoms.
• the hydrophobic chain will comprise between 4 and 16 carbon atoms and, more preferably, between about 4 and about 10 carbon atoms.
• the hydrophobic chain is preferably substituted directly on the nitrogen, sulfur, or phosphorous atoms. However, in certain instances such, for example, as in heterocyclic quaternary ammonium compounds, it may be present else- Where in the molecule, e.g., on the heterocyclic ring.
• the upper limit on the molecular Weight and length of the hydrophobic chain in such onium compounds is preferably determined by the solubility and mobility of the complex of such compounds and the dye developers in the aqueous alkaline processing solution.
• onium compounds containing a hydrophobic chain mention may be made of I-octyLZ-methylpyridinium p-toluene sulfonate, octyltrimethylammonium bromide, lauryltrimethylammonium bromide, l-octyl-l-methylpiperidinium methosulfate, octyltrimethylphosphonium bromide, and octyldimethylsulfonium p-toluene sulfonate.
• Hydrophobic substituents which have been found particularly useful in the onium compounds of this invention are the aralkyls .and especially the phenalkyls. Onium compounds containing such substituents have been found especially useful in producing a marked improvement in both the density and the highlights. Particularly good results are obtained when the phenalkyl substituents are selected from those wherein the alkyl portion of the molecule comprises 1 to 4 carbon atoms, e.g., benzyl, phenethyl, phenylpropyl and phenylbutyl radicals.
• a class of onium compounds which has been found especially useful are those which contain a reactive methyl group, Le, a methyl group which in allrali is capable of forming a methylene base. Such compounds, in addition to improving the density of highlights, also provide improved color separation, i.e., the transfer of the dye de velopers is more closely controlled by the silver halide emulsion with which each is associated. Pyridiniurri quaternary ammonium compounds having a methyl substituent in the 2. or 4 positions of the heterocyclic ring have been found especially useful as such onium compounds possessing a reactive methyl group.
• the preerred 2 and 4 methyl-substituted pyridinium compounds are those wherein the nitrogen atoms is substituted by a phenalkyl group and especially by a phenalkyl in which the alkyl portion of the molecule comprises 1 to 4 carbon atoms.
• Preferred compounds within this group are l-(fi-phenethyl)-2-methylpyridiniurn bromide and 1- benzyl-2-methylpyridinium bromide.
• a combination of onium compounds is employed. Through the use of such a combination, one may strike a desired balance between the increase in density and the improvement in the highlights.
• One such combination comprises using an onium compound of small molecular "size such, for example, as those mentioned above, which are devoid of hydrophobic chains comprising more than 3 carbon atoms, with an onium compound containing a hydrophobic chain of at least 4 carbon atoms.
• One of the pre ferred combinations comprises using an onium compound of small molecular size with a large onium compound such as mentioned above which also contains a reactive methyl group. Such a combination is particularly eifective in producing transfer images having increased density and improved highlights and color separation.
• the onium compound possessing the active methyl group is substituted by a phenalkyl group.
• a phenalkyl group As an example of such an especially use ful combination, mention may be made of the use of N-ethylpyridinium bromide in combination with N-([i phenethyl)-2-methylpyridinium bromide.
• a higher molecular weight onium compound e.g., lauryl-trimethylammonium bromide is also used in the combination. The use of such higher molecular weight onium compounds further improves the highlights of the transfer image.
• the ability of the onium compounds to improve the color separation and highlights will be proportional .to the ease with which such onium compounds are adsorbed on the silver halide grains of the light- I sensitive emulsions.
• an aqueous alkaline processing solution which includes in part at least one organic, water-miscible solvent.
• organic, water-miscible solvent examples include dioxane, N,N-dimethy1 ethanolamine, N,N-diethyl ethanolamine, tetrahydrofuran, and diethylaminopropanediol.
• Processing solutions comprising about of the organic, water-miscible solvent have been employed; however, it should be understood that this percentage may be varied to suit particular needs.
• the onium compounds may be introduced into the processes by various methods.
• the onium compounds are incorporated directly into the processing solution and inbibed into the photosensitive element along with the other reagents used.
• the onium compounds are disposed in the imagereceiving element and during processing they are solubilized therefrom and transferred to the photosensitive element so as to be present during development.
• the onium compounds are disposed in the photosensitive element, e.g., in special reagent layers, in the dye developer layers, etc. When using the latter embodiment, care should be taken to prevent the onium compounds from desensitizing the emul- 510115.
• the amount of onium compounds used may be varied to suit particular needs. Generally, good results have been obtained by using processing solutions comprising about 1 to 10% of the onium compounds and especially good results have been obtained by using processing solutions comprising 2 to 4% of such compounds.
• antifoggants tend to offset the fogging which may occur as an effect of the onium compounds ability to accelerate development.
• antifoggants which have been found useful, mention may be made of thioacetanilide, S-methylbenzimidazole, S-nitrobenzimidazole, 2 aminobenzimidazole and 1 phenyl 5- mercaptotetrazole.
• Example 1 A photosensitive element was prepared by coating 2. gelatin-subcoated cellulose acetate film support with the following coating solutions:
• a te-trahydrofuranacetone solution (1 to l by volume) comprising 5.5% of 1,4-bis-[,3-(2',5-dihydroxyphenyl)-isopropylamino]-anthraquinone (a cyan dye deveolper), about 0.8% of Resofiex 296 (trade name of Cambridge Industries (10., Inc., Cambridge, Mass, for an alkyd resinous plasticizer) and 2% cellulose acetate hydrogen phthalate.
• a 'tetrahydrofuran-acetone solution (1 to l by volume) comprising 3.5% of 2-'[p-(2',5'-dihydroxyphenethyD-phenylazo]-4-n-propoXy-l-naphthol (a magenta dye developer), 2% of cellulose acetate hydrogen phthalate and 0.4% of Resofiex 296.
• the above photosensitive element was exposed and then processed by spreading an aqueous processing solution comprising I Percent 1-phenyl-3-pyrazolidone 1.2 2,5-bis-ethyleniminohydroquinone 0.9
• Example 2 A photosensitive element was prepared, exposed and processed in a manner similar to that employed in Example 1 except that an aqueous processing solution comprising:
• Example 3 A photosensitive element was prepared, exposed and processed in a manner similar to that employed in Example 1 except that an aqueous processing solution comprising:
• Example 4 A photosensitive element was prepared and processed in a manner similar to that employed in Example 1 except that an aqueous processing solution comprising:
• Example 5 A photosensitive element was prepared and processed in a manner similar to that employed in Example 1 except that an aqueous processing solution comprising:
• Example 6 A photosensitive element was prepared and processed in a manner similar to that employed in Example 1 except that an aqueous processing solution comprising:
• Example 7 An aqueous processing solution comprising:
• Example 1 was used to process an exposed photosensitive element such as employed in Example 1.
• Example 8 An aqueous processing solution comprising:
• Example 9 An aqueous processing solution comprising:
• Example l was used to process an exposed photosensitive element prepared in a manner similar to that employed in Example l.
• the following examples utilize a photosensitive element prepared in a manner similar to that disclosed above except that (a) the dye developers were dissolved in a Waterimmiscible solvent and dispersed in gelatin rather than placed in a cellulose acetate hydrogen phthalate layer; (b) a single gelatin interlayer was used in place of the polyvinyl alcohol and cellulose acetate hydrogen phthalatecellulose acetate layer; and (c) the outer blue-sensitive emulsion was overcoated with a thin gelatin layer comprising about 15 mg. per square foot of 4-methylphenylhydroquinone.
• Example 10 An all gelatin photosensitive element similar to that described above was exposed and processed by spreading an aqueous processing composition comprising:
• Example 11 A processing solution comprising:
• Example 10 was used to process an exposed photosensitive element in a manner similar to that employed in Example 10.
• Example 12 A photosensitive element similar to that employed in Example was processed in a manner similar to that employed in Example 10 except using a processing solution comprising:
• Example 14 The process of Example 10 was repeated except that an aqueous processing solution comprising:
• Example 15 The process of Example 10 was repeated except that an aqueous processing solution comprising:
• Example 16 The process of Example 10 was repeated except that an aqueous processing solution comprising:
• Example 17 The process of Example 10 was carried out except that an aqueous processing solution comprising:
• Example 18 The process of Example 10 was repeated except that an aqueous processing solution comprising the followmg:
• Example 4 the process is carried out in the presence of a compound containing two quaternary ammonium radicals.
• onium compound as used herein is intended to include compounds containing one or more onium radicals.
• Transfer images were prepared from one negative by using an aqueous processing solution containing no onium compounds (Solution A), from a second negative by using an aqueous solution containing the oniums (Solution B) and from a third negative by using an aqueous process ing solution comprising both the oniums and a watermiscible solvent (Solution C).
• the solutions comprised the following.
• Solution A Percent Sodium hydroxide 4.0 Sodium carboxymethyl cellulose 3.5 S-nitrobenzimidazole 0.5
• SOLUTION A SOLUTION C Density Exposure Cyan Magenta Yellow Blue and Green -Q 1. 31 0.12 0. 13 Red and Blue 0.20 0. 65 0. 12 Red and Green 0.12 0.16 1. 24
• the dye developers which are used in the processes of this invention are compounds which contain in the same molecule both the chromophoric system of a dye and also a silver halide developing function. Particularly useful results have been obtained when the onium compounds were. used in conjunction with dye developers comprising hydroxy-substituted benzenoid silver halide developing radicals and especially benzenoid silver halide radicals which are substituted by at least two hydroxy groups, e.g., hydroquinone and catechol radicals.
• Representative dye developers for use in the processes of this invention are disclosed in the previously mentioned US. application of Howard G. Rogers, Serial No. 748,421, now US. Patent No. 2,983,- 606. Additional useful dye developers are described in the following copending US.. applications:
• aqueous solutions used'in the processes of this invention are alkaline in nature and preferably should have a pH of at least 12.
• alkaline materials which may be used are sodium hydroxide and potassium hydroxide, etc.
• an all quaternary processing solution may be employed by using quaternary hydroxides such as choline and tetrarnethylammonium hydroxide in place of the alkali metal hydroxides.
• the onium compounds are used in combination with a silver halide developer in addition to the dye developers.
• the silver halide developers which have been found especially useful in this embodiment are the hydroxyl-substituted aryl developers, for example, toluhydroquinone, 5,8-dihydro-1,4-naphthohydroquinone, o-
• the onium compounds for use in the processes of this invention will be difiusible in the alkali-permeable film-forming materials which are used in the emulsion and other layers of the photosensitive element.
• Many alkali-permeable, film-forming materials are available for this use and the particular materials employed will vary depending on ones particular choice.
• film-forming materials which have been used, mention may be made of gelatin, polyvinyl alcohol and cellulose acetate hydrogen phthalate.
• the oniums will be preferably colorless so as not to alter the color of the transfer image.
• the coaction of the onium compounds with the dye developers was evidenced by a dye diffusion front test wherein the initial diffusion rate of 2-[p-(2',5'-dihydroxyphenethyl -phenylazo] -4-n-propoXy-1-naphthol (magenta dye developer) through gelatin was measured using a processing solution containing no quaternary ammonium compound and using a processing solution containing N- ⁇ S-phenethyl-a-picolinium bromide. It was found that the quaternary ammonium compound reduced the initial diffusion rate of the dye developer. It is believed that this reduction in the initial difiusion rate of the dye developers tends to prevent premature transfer and thus promotes an improvement in the highlights.
• Such processes of this invention are especially useful in composite film units intended for use in a Polaroid Land Camera, made by Polaroid Corporation, Cambridge 39, Massachusetts, or a similar camera structure such, for example, as the camera forming the subject matter of US. Patent No. 2,435,717, issued to Edwin H. Land on February 10, 1948.
• such composite film units comprise a photosensitive element, such as the integral multilayer element heretofore described, an imagereceiving element and a rupturable pod containing an aqueous alkaline processing solution.
• the photosensitive element, image-receiving element and pod are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements.
• the nature and construction of the pods used in such rolls are well known to the art. See, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.
• dye developer as used herein is intended to include color-shifted dye developers such as those disclosed in the copending application of Howard G. Rogers, Serial No. 789,080, filed January 26, 1957.
• a process of forming a transfer image in color which comprises exposing a photosensitive element comprising at least one silver halide emulsion, each of said silver halide emulsions having associated therewith a dye dei l veloper, each of said dye developers containing a hydroxysubstituted benzeuoid silver halide developing radical, developing said exposed photosensitive element, forming in undeveloped areas of each said silver halide emulsion, as a function of said development, an imagewise distribution of said associated dye developer in unoxidized, diilusible condition, and transferring, by diffusion, at least a portion of each said imagewise distribution of unoxidized dye developer to a superposed image-receiving layer to form said color transfer image, said process including the step of efi'ecting said development and transfer in the presence of at least one onium compound selected from .the group consisting of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds
• heterocyclic quaternary ammonium compound is a derivative of pyridine.
• heterocyclic quaternary ammonium compound contains a phenalkyl substituent on the pentavalent nitrogen atom.
• aqueous alkaline processing solution includes a water-miscible organic solvent.
• a process as defined in claim 15 wherein the hydro phobic chain of said second onium compound comprises from 4 to 16 carbon atoms.
• hydrophobic chain of said second onium compound comprises from 4 to 10 carbon atoms.
• a photographic product comprising (a) a photosensitive element, said photosensitive el'ment comprising a support carrying at least one silver halide emulsion, each said silver halide emulsion having associated therewith a dye developer, each of said dye developers containing a hydroXy-substituted benzenoid silver halide developing radical, (b) an image-receiving element comprising a support carrying an image-receiving layer, and (c) a rupturable container releasably holding an aqueous alkaline processing solution, said aqueous alkaline processing solution including an onium compound selected from the group consisting of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds, said photosensitive element and said imagereceiving element being capable of being superposed on each other with said rupturable containerpositioned therebetween so as to release said processing solution, upon rupture of said container, to permeate said silver halide emul
• a photographic product as defined in claim 24, wherein said photosensitive element comprises a support carrying a red-sensitive silver halide emulsion stratum, 'a green-sensitive silver halide emulsion stratum, and a blue-sensitive silver halide emulsion stratum, each of said silver halide emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer, and a yellow dye developer, each said dye developer being disposed in an alkali-permeable layer behind its associated silver halide emulsion.
• a photographic developer composition comprising an aqueous alkaline solution comprisin'gan alkali metal hydroxide, a dye developer, said dye developer containing a hydroxy-substituted benzenoid silver halide developing radical, and at least one colorless onium compound selected from the group consisting of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds.
• a process of forming a'transfer image in color which comprises exposing a photosensitive element comprising at least one silver halide emulsion, each of said silver halide emulsions having associated therewith a dye developer, each of said dye developers containing a hydroXy-substituted benzenoid silver halide developing radical, developing said exposed photosensitive element, forming in undeveloped areas of each said silver halide emulsion, as a function of said development, an imagewise distribution of said associated dye developer in unoxidized, diffusible condition, and transferring, by diffusion, at least a portion of each said imagewise distribution of unoxidized dye developer to a superposed image receiving layer to form said color transfer image, said process including the step of effecting said development and transfer in the presence of at least one onium compound selected from the group consisting of quaternary ammonium, quaternary phosphonium and tertiary sulfonium compounds, said onium compound being initially positioned in one of (a) said photo-
• a process as defined in claim 30 wherein said onium compound is initially positioned in said image-receiving layer, said aqueous alkaline processing solution is applied between said image-receiving element and said photosensitive element, and said onium compound is solubilized by said aqueous alkaline processing solution and transferred by diifusion to each said silver halide emul- SlOIl.

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• Photosensitive Polymer And Photoresist Processing (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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