BE615532A - - Google Patents

Description

       

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  New inversion-transfer process in colors and products for its implementation.



   The present invention relates to photography and, more particularly, to a method of forming color images by inversion-transfer, as well as to the products suitable for the implementation of this method.



   A color inversion-transfer process has been described, for example, in French patent 1,168,292, applied for on December 29, 1956. As indicated in this patent, a photographic product comprising layers of emulsion is used. with silver halides and layers containing "diffusible coloring developers, these coloring developers which will be referred to hereinafter as developing dyes consisting of dyes the molecule of which contains a developing group for the halides

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 silver, these products are exposed to form a latent image in the silver halide emulsions and treated with a basic processing liquid which diffuses into the emulsion layers and the colorant-containing layers. developers ,.

   these then converting the latent images into silver images.



  At the same time, oxidation products of the developing dyes are formed in situ with the silver images, oxidation products which are relatively non-diffusible in the colloid which constitutes the binder of the layers. The fact that the ordered developer dyes do not diffuse is apparently due, at least in part, to a reduction in the solubility in the basic processing liquid and, perhaps also, to a tanning or hardening action of the developer. oxidized on the colloid constituting the binder of the layers, action having the effect of slowing down the diffusion of the oxidized developing dyes.

   The unoxidized dye developers which remain in the layers in an image dependent topographic distribution are transferred by diffusion onto a receiving material superimposed on the photographic material, to the practically total exclusion of the silver image and the oxidized developing dye. , to form an image of positive dye in the recipient product.



   When using a photographic material containing several layers of silver halide emulsions, each sensitized to a different spectral region, and developing dyes whose respective colors are complementary to the sensitivities of the layers of silver. emulsions are present in the latter or in layers adjacent thereto, the developing dyes are oxidized, upon treatment with the basic treatment liquid, and rendered non-diffusible in the developed regions of the layers. emulsion, while the residual developing dyes from the undeveloped regions, distributed in a positive image of the original, are transferred by diffusion and registration to the receiving product to form a color image.



   It has been found according to the invention that when images of developer dye are transferred to the recipient product at

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 From sensitive products which have been stored for some time under unfavorable temperature and humidity conditions, the images tend to have a smaller density than desired, this density also being smaller than that which would be expected. assumed to be obtained from the amount of developer dye available at the time of transfer.



   It has been found that these significantly higher image densities can be obtained if a photographic product is used comprising a support on which are superimposed several layers of emulsion of different sensitivity, at least one of the layers of emulsion. - ion containing a compound selected from hydroxylated and aminated tri-, tetra- and penta-azaindenes, a developing dye being adjacent to the silver halides in each emulsion layer, said developing dye being a compound which is at the same time a developer of the silver halides and a dye.



  The improvement in density appears to be the result of each developing dye, without its initial unoxidized form, image-diffusing to the receiving layer, without being contaminated by other reagents or by the reaction products of the process.



   The objects of the invention are therefore in particular - a photosensitive product making it possible to obtain developing dye images of improved density, - a process of the type of color inversion-transfer processes, using said product.



   In the following description, typical sensitive products will be described, as well as processing solutions and various processing modes which provide the most useful dye images, and finally receptor products suitable for receiving the transferred dye images. on these products by diffusion. There will also be described cameras and processing apparatus particularly suited to the preparation of developing dye images.



   In a typical embodiment, a sensitive product comprising several layers is exposed to a color original.

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 silver halide emulsion sensitive to different regions of the visible spectrum with adjoining developing dyes which may be of the color :; complementary to those to which the corresponding emulsion layers are sensitive and preferably hydroquinone derivatives.

   The product is then treated by moistening it with an alkaline treating solution, for example, a solution containing hydroxyethylcellulose as a thickener, contacted with the receiving layer, preferably in the presence of onium compounds, especially. of a quaternary ammonium salt, to develop the silver halides exposed in the emulsion layers and to render the developing dyes non-diffusible in the areas where development has taken place, the developing dyes in the non-areas. developed being imaged by diffusion and registration on the receiving layer, to ultimately provide a full color developing dye image on that layer, which image exhibits improved density.



   In a typical embodiment, the sensitive product contains gelatin-based emulsion layers which are sensitive to red, green and blue respectively, at least one of these layers and, preferably, all containing one of these precise azaindenes. - tees. The product also contains under each emulsion layer a non-photosensitive gelatin layer which contains a complementary color developing dye (blue-green, magenta or yellow), and gelatin interlayers separating the middle emulsion layer. and the corresponding developer dye underlayer of the other two emulsion layers and the other two developer dye layers. In addition, a hydroquinone derivative as described below is preferably present in one of the layers of the product.



   ..on has the receiving product comprising a support and receiving layer applied to this support (which can contain the so that it receives the dye images yes are trans- @
 EMI4.1
 0 "-., ...., gµEees. By diffusion of the sensitive product, a frangible sachet containing ','; ' : 'e': QltÍt1C? n. alkaline treatment being placed between the probable; ¯e1:

   the receiving product..After the breakage of the

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 chet, for example, after passing the assembly between the rollers of a camera so as to distribute the contents of the container uniformly over a predetermined area of the sensitive product,}.! solution penetrates into the emulsion layers and as a result, the latent images develop silver and the developing dyes in the developing areas are immobilized and made non-diffusible. The unreacted developing dyes then diffuse in register images on the receiving layer where they form dye images.



   According to a variant, the developing dyes can be incorporated in the sensitive emulsion layers containing the azaindene derivatives, hydroquinone derivatives possibly being present in the layer furthest from the support. Likewise, this product can be used to obtain developer dye images of improved density.



   In the above process using developer dyes, it has been found that, due to the ineffectiveness of the developer dyes as silver halide developers, the lack of discrimination of the developer dyes for the silver halides they must develop and other factors, when sensitive products comprising several layers of emulsion of different chromatic sensitivity and adjacent developing dyes for reproduction in subtractive colors are used in the process of the invention. Products of emulsion development tend to affect the development of other emulsion layers, diffusion of a developing dye from a lower layer can be prevented by a developing dye or other substance from one layer. superior,

   depletion of the treatment solution by an outer layer may affect the development of a lower layer, one layer may not develop to the same degree as another layer, and one of the developing dyes may not be immobilized enough to prevent it from diffusing, causing color contamination of dye images of another color. Likewise, a given developer dye

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 may develop some silver halide grains in an emulsion layer which does not correspond to it, so that an insufficient amount of this developing dye is available for transfer and the corresponding colors are not available. not saturated.

   Thus, a magenta developer dye. may develop certain red-sensitive silver halide grains and be immobilized, thereby decreasing the amount of magenta dye available to produce the red colors which thus appear unsaturated.



  When the hydroquinone derivatives described below and the azaindenes are present in sensitive products, these disadvantageous effects appear less.



   It has already been stated that the onium compounds are preferably used in forming the developing dye images. These products are used particularly with azaindenes to avoid the above drawbacks, such as color contamination. It is believed that the onium compounds react with the developing dyes to form salts and that the improvements in color contamination, loss of saturation and minimum density are due at least in part to the effect of color. formation of these salts on the solubility and diffusibility of developing dyes.

   It is evident that the onium compounds temporarily retard the migration of the developing dyes, so that the initial diffusion rates of the developing dyes are reduced and an even greater amount of the developing dye is transferred from the plaques. less exposed to increase density. The beneficial effects of the hydroquinone derivatives include a decrease in the contamination of colors in the prints, which is apparently due to their ability to more completely and uniformly immobilize the developing dyes in the regions of development.



   "Color contamination" usually appears in proofs as denaturing one or more cuts by one or more other colors and may be due to one or more developing dyes not being present. suf-

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 completely immobilized and are transferred from the regions where they should have been immobilized.

   "Loss of saturation" is a defect in the color quality of the proofs apparently due to the fact that a developing dye has developed silver halide grains in an emulsion layer on which it should not have acted. , pa: example that the magenta developer dye has developed red-sensitive silver halide grains and therefore there is too much magenta developer dye immobilized, so the reds thus lack magenta .



   Hydroxylated and aminated tri-, tetra- and penta-axaindenes useful in the emulsions according to the invention, in an amount of between approximately 1 g and 12 g per mole of silver halide, are, for example,
 EMI7.1
 2,4-dihydroxy-6-methyl-1,3a, 7-riazaindene, 2,5-dimethyl-7-hydroxy-1,4,7a-triazaindene, 5ino-7-hydroxp-2-methyl-1 , 4,7a-triazaindene, 5-earboxy-4-h "Ydr.ozy-1,3,3a, 7-tetraazaindene, l, 2-bis - (, 4-hydro2y-6-aiethyl-l, 3 , 3a, 7-tetraazaindene-5-7l) -ethane, 1,2,3,4-tetrakis- (4 hydroxy-6-methyl-1,3,3a, 7-tetr.aazaindene-2-y -butane , 2-amino-5-carboxy-4-hydroxy-1,3,3a, 7-tetraazaindene, 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene, 4-hydroxy-2- beta-h, ydroxpethyl-b methyl-1,3,3a, 7-tetraazaindene, 5-carbethoxy-4-hydroxy-1,3,3a, 7-tetraazaindene, 7-hydroxy-1,2,3,4 , 6-pentaazaindene, 2,4-dihyâroxy-6-nxethyl-l, 3a,

  7-tetraasaindene, 4.-bydroxy-2-gamma-hydroxypropyl-ô-methyl-1,3,3a, 7-tetraazaindene, 4-hydroay-2-ridyl) -bétlYl-1,3,3.a, '1-Tetraazaindene, 4.-hydroxy-6-ffletbyl-1,2,3,3a, 7-pentaazaindene, 5-amino-2- (para-carboxyphenyl) -7-hydro: xy-1,3, 4,6-pentaazainâene.



   Other useful azaindenes are described in Belgian patent 529,819, filed June 22, 1954, Belgian patent 530,062, filed July 1, 1954, Belgian patent 548,637, filed June 15, 1956, Belgian patent 549,178, filed June 30, 1956 , to Belgian patent 530,063, applied for July 1, 1954, to Belgian patent 543,978, applied for December 27, 1955, to Belgian patent 561,108, applied for September 25, 1957 and in a publication by Zeitschrift für Wiss. Phot. 47 pages 2 to 28 (1952).



   Onium compounds have been used for some time in photography. For example, quaternary ammonium compounds without surface activity have been used as development accelerators. French patents 949.227, 949.228 and 949.229, all

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 filed on August 11, 1945 describe the use of quaternary ammonium compounds, quaternary phosphonium compounds and tertiary sulfonium compounds as sensitizers of silver halide emulsions. Notwithstanding these known facts, it should be noted the reported results obtained when using onium compounds in conjunction with developing dyes in reverse transfer processes.

   In the processes described in the French patents indicated in this paragraph, the use of the onium compounds has the effect of increasing the silver density of the negative; however, this increase in density, in these processes, takes place within the exposed negative ranges and can be attributed to the above stated ability of the onium compounds to sensitize an emulsion or to accelerate development. To which the present invention relates, when there is an increase in density, this takes place in the positive image and is mainly due to the fact that more developing dye has been added. transferred from unexposed regions of the negative.



  The fact that the onium compounds and the azaindenes cooperate with the developing dyes so as to intensify the transfer of the latter from the unexposed areas of the negative cannot be inferred from the previous use which has been made of these compounds as sensitizers or as development accelerators.



   The fact that the onium compounds also have the effect, especially in the presence of hydroquinone compounds, of preventing the transfer of oxidized developing dyes from the exposed regions and thus improving the regions of the image which correspond to the regions of the image. great lights is also unexpected. This latter improvement is believed to be due to the ability of the onium compounds to control, especially within the exposed ranges, the diffusivity of these developing dyes.



   Particularly advantageous results are obtained when using quaternary ammonium compounds. Quaternary ammonium compounds are known to be organic compounds

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 which contain a petavalent nitrogen atom. In general, they can be regarded as deriving from ammonium compounds in which the four valences generally satisfied by the hydrogen atoms are satisfied by organic radicals * In general, the organic radicals are directly linked to the pentavalent nitrogen by a single or double carbon-nitrogen bond.

   In this specification, the term quaternary ammonium covers compounds where pentavalent nitrogen is one of the nuclear atomos of a heterocyclic nucleus, as well as compounds where the four valences are satisfied by separate organic radicals. , for example, as in the case of tetrallcoylated quaternary ammonium compounds.



  Examples of quaternary ammonium compounds are those compounds which can be represented by the following formulas
 EMI9.1
 where R represents an organic radical, Y an anion, for example a hydroxyl or toluenesulfonate group, a bromine or chlorine atom, etc. and Z the atoms necessary to complete a heterocyclic ring.

   Specific examples of compounds corresponding to formulas I, II and III are tetraethylammonium bromide, N-ethylpyridinium bromide, N, N-diethylpiperidinium bromide, ethylene-bis-piperidinium bromide, 1-ethylpyridinium bromide,;

   1-Phenetyl-3-picolinium bromide, tetraalkylammonium salts, cetyltrimethylammonium bromide, polyalkyl oxides, two-functional quaternary ammonium salt, such as bis-

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 polyethylene oxide pyridinium perchlorate, the mentioned heterocyclic quaternary ammonium salts which form methyl bases
 EMI10.1
 lene, such as 3-methyl-2-ethylisoquinolinium bromide, 3-methylisoquinolinium methyl -para-toluenesulfonate, 1-ethyl-2-metkyl¯3-phenethyl-benzi3rixlazolium bromide, 5,6 betaine - Dichloro-1-ethyl-2-methyl-3- (3-sulfobutyl) -benzimidazolium and the pyridinium salts indicated below ... below.



   Tertiary sulfonium and quaternary phosphonium compounds can be represented respectively by the formulas (IV) (R) 3 S + X- (V) (R4) P + X- where R represents an organic radical, for example an al group. - coyl, aralkyl, aryl, etc., and X an anion such as a hydroxyl or toluenesulfonate group, a bromine or chlorine atom, etc.



  Examples of tertiary sulfonium and quaternary phosphonium compounds are lauryldimethylsulfonium p-toluenesulfonate, nonyldimethylsulfonium p-toluenesulfonate and octyldimethylsulfonium p-toluenesulfonate, butyldimethylsulfonium bromide, triethylsulfonium bromide, triethylsulfonium bromide, tetraethylphosphonium, dimethylsul- para-toluenesulfonate
 EMI10.2
 fonium, dodecyldimethylsulfonium para-toluenesulfonate, decyldimethylsulfonium para-toluenesulfonate and ethylene-bis-onnethyltriethylphosphonium bromide.



   The onium compounds can be used in the hydroxide state or in the salt state. When used in the form of salts, the anion can be derived from any acid. However, when the anion is an iodide anion, appropriate precautions must be taken, since this anion has harmful effects on the emulsion. Particularly satisfactory results are obtained when the onium compounds are used in the bromide state.



   Heterocyclic quaternary ammonium compounds

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 particularly effective which form the methylene bases diffusible in basic solution correspond to the general formula
 EMI11.1
 where D represents the non-metallic atoms which complete the heterocyclic ring of the quaternary ammonium compound containing one or more reactive groups -CH2R 'attached at one or more positions of the ring, the other positions of the ring carrying or not having substituents, such as a nucleus of the series of pyridine, quinoline, benzoquinoline, benzoxazole, benzoselenazole, thiazole, benzothiazole, naphthothiazole, benzimidazole, isoquinoline, etc., It being zero or 1 , R a substituted or unsubstituted alkyl, aryl or aralkyl group from the benzene series,

   the alkyl groups preferably being lower alkyl groups (one or four carbon atoms), R ′ a hydrogen atom or one of the groups represented by R and X the OH- ion or an acid anion, such as than Br-, CH3SO4 or CH3- # -SO3. One or more of these quaternary ammonium compounds can be used, alone or in combination with onium compounds of formula I, II, III, IV and V and advantageously, they are incorporated in the treatment liquid, in the receiving product or in to both, or less advantageously to the photographic product, their presence improving the quality of the print by a process that is not well known. When hydroquinone compounds are also present, an interaction occurs resulting in a much better result than when only the hydroquinone compound or the quaternary compound is present.

   The trials in. The resulting colors exhibit much less color contamination, as well as better color saturation, density and contrast.

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   The amount of onium compound which can be used varies depending on the nature thereof. When incorporated into the treatment liquid, useful results are obtained when it is in a proportion between 2/1000 and 150/1000. In some cases, a proportion between 2/1000 and 30/1000 is preferable.



  Likewise, when it is incorporated into the photographic material or the receiving material, the amount of onium compound to be used varies depending on the nature of this compound.



   According to a particular embodiment of the invention, the quaternary ammonium compounds used are pyridinium salts which form diffusible methylene bases and which have formula (VI), the pyridinium nucleus bearing in one at least in positions 2, 4 and 6, one to three reactive methyl groups -CH2R ', such as a lower alkyl group (methyl, ethyl, propyl) optionally substituted, for example by a hydroxyl group (hydroxyethyl, etc.), which reactive methyl groups act as precursors of methylene bases. The 3 and 5 positions may or may not have substituents, such as halogen atoms or lower alkyl or haloalkyl groups, for example chlorine atoms or methyl, ethyl, propyl or chloroethyl groups.



   Typical salts of formula (VI) are as follows.



  1- (3-Bromopropyl) -2-picolinium 1-Benzyl-2-picolinium p-toluenesulfonate bromide 1-Phenethyl-2-picolinium bromide
 EMI12.1
 1-Garuna-phenylpropyl-2-piçolinium bromide 2,1-dimethyl-1-phenethylpyridinium bromide 2,6-dimethyl-1-phenethylpyridinium bromide 5-ethyl-2-methyl-1-phenétbylpvriii-liua bromide 2-ethyl-1-phenethylpyridinium 1 - (DT-bromopyridinium) -propyl7-2- picolinium p-toluenesulfonate

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 EMI13.1
 
 EMI13.2
 Dan.b, ydro-1- (4-sulfobutyl} -2-picolinium hydroxide
 EMI13.3
 alpha-picolin-beta-naphthoyl methylbromide
 EMI13.4
 1-beta-phenylcarbamoyloxyethyl-2-picolinium bromide
 EMI13.5
 1-methyl-2-picolinium p-toluenesulfonate
 EMI13.6
 1-phenethyl-2,4 bromide,

  6-Trimethylpyridinium 1-Phenethyl-4-, U-propylpyildinium bromide 4-gamma-hydroxypropyl-1-phenétbylpyridinium bromide 1-n-hetpty1-2-picolinium bromide.



   A number of pyridinium salts of the general formula given above do not form methylene bases sufficiently diffusible in basic medium to be of any utility in the process according to the invention. These are, for example, the bromides of ln-decyl-2-picolinium, 1,2-dibenzylpyridinium, 6-amino-1-phenethyl-2-picolinium, 2-amino-1-phenethyl-4- picolinium

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 EMI14.1
 2-benzyl-1-phenethylpyridinium and I + -benzyl-1-pnenethylpyridinium.



   The bromides of 1-phenethylpyridinium, of 1-ethylpyridinium, and of 1-phenethyl-3-picolinium and of 1-n-nonylpyridinium p-toluenesulfonate, which do not form methylene bases in basic medium, are also less useful.



   The hydroquinones which have the required properties and which can be incorporated according to the process of the invention should be practically colorless and practically insoluble in water, but soluble and diffusible in a basic medium in colloid layers. such as gelatin.

   Examples of such compounds are given below: Phenylhydroquinone 2'-hydroxyphenylhydroquinone Phenoxyhydroquinone 4'-methylphenylhydroquinone 1,4-dihydroxynaphthalene 2- (4-aminophenethyl) -5-bromobydroquinone
 EMI14.2
 2- (h-aminophenethyl) -5-methyllydroquinone 4'-am! Nophenethylhydroquinone 2,5-dimethoxyhydroquinone 2,5-dibutoxyhydroquinone m-xylohydroquinone bromohydroquinone 3,6-dichlorohydroquinone
 EMI14.3
 2-dimethylaminometbytoluhydroquinone 2-cyclohexylhydroquinone sec.

   butylhydroquinone 2,5-dichlorohydroquinone
 EMI14.4
 2,5-dü sopropylhydroquinone 2,5-diiodohydroquinone 3-chlorotoluhydroquinone Tetrachlorohydroquinone 2,5-diphenylhydroquinone 2,5-dresorcylhydroquinone

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 2,5-dioctylhydroquinone Dodec.ylhydroquinone
Useful hydroquinone compounds are particularly distinguished from developer dyes which contain a hydroquinonyl group in that they are substantially colorless and therefore do not color the test.



   For carrying out the process, the silver halide emulsions and the developing dyes are preferably in the vicinity of the hydroquinone compounds and quaternary ammonium salts. In other words, the quaternary salt can be found in the basic processing liquid or in the recipient product or both, and less preferably in the sensitive product, while the hydroquinone compound is in any of the following. layers of the photographic material, for example, in an overcoat, in an emulsion layer, in a developer dye layer, or in the receiver sheet. Thus, the receiving sheet or layer may consist of a mordant of the developing dye, for example poly-4-vinylpyridine and, in addition, of at least one of the above hydroquinone derivatives.

   Likewise, the receiving layer or sheet may contain the combination of a mordant for the developing dye, at least one of the hydroquinone derivatives and at least one of the above-mentioned onium compounds, particularly the ammonium compounds. heterocyclic quaternaries forming methylene bases. For certain purposes, the hydroquinone derivatives may be present in the treatment liquid containing the hydroxyethylcellulose. However, according to the invention, the use in liquid is much less advantageous, since the hydroquinone derivatives are unstable in such solutions and readily undergo oxidation accompanied by parasitic coloring of the tests, unless prepare and store in the absence of air or take other precautions to avoid oxidation.



   The hydroquinone derivatives are preferably incorporated

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 to emulsion layers, overcoat, interlayer and other layers as a dispersion in a hydrophilic colloidal binder. Hydroquinone derivatives can be dissolved in an alkaline solution and precipitated in aqueous gelatin solutions by increasing the acidity of the solution. However, this procedure is one of the least advantageous, because of the instability of these compounds in alkaline solutions. Can the hydroquinone derivatives be dissolved in a solvent, such as lower alcohol, and precipitated from solutions? - aqueous gelatin for coating on the sensitive product.

   They can be added to gelatin solutions which are passed through the bead mill to reduce crystal size. However, one dissolves, preferably, the hy. droquinones in a low molecular weight, water insoluble organic crystalloldal solvent which is permeable to solution. alkaline treatment and which has a boiling point above about 175 ° C, such as dibutyl phthalate, and they are added to the aqueous gelatin solution which is then passed through a colloid mill until reaching the desired degree of division. An auxiliary organic solvent can also be used, for example a solvent which has a solubility in water greater than that of the crystalline solvent and on the order of at least about two parts per hundred parts of water.

   Thus, the auxiliary organic solvent can be washed away from the cooled gelatin dispersion in the presence of the other solvent. The auxiliary solvent may be a solvent having a boiling point at least about 25 ° C lower than that of the crystalline solvent, so that it can be removed by volatilization during the drying of a product. layer leaving the hydroquinone derivative dispersed in the crystalloidal solvent alone. As a result, the hydroquinone derivatives are rapidly and uniformly dissolved in the alkaline processing composition and distributed throughout the sensitive product to produce a more uniform development than when the hydroquinone derivatives are incorporated into the product by another. way.

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   The hydroquinone derivatives can be used in one or more layers of the sensitive product in an amount equal to approximately
107 mg to 1070mg or more per square meter. However, the amount used depends in part on the amount of silver halides of the layer in which the hydroquinone derivative is incorporated, the amount of developing dye and the amount of pyridinium salt contained in the sensitive product or in the treatment solution of the receiving product. In some cases it may be desirable to form a complex of hydroquinone derivative by reaction with sulfur dioxide in a known manner and to incorporate the complex into the overcoat, in the external emulsion layer. - ne or in another layer of the sensitive product.

   These complexes of hydroquinone and sulfur dioxide are more stable than the hydroquinone derivatives themselves.



   The developer dyes for use in the emulsion layers or in adjacent layers are compounds which are simultaneously developers of silver halides and dyes. They are characterized by their property of being practically not diffusible in the colloid layers at neutral pH, but being so in the presence of basic processing liquids * In the majority of cases, the developing dyes are insoluble in water, which usually requires the use of organic solvents to incorporate them into the colloid layers of photographic products.

   In all other respects, the solubility of the developing dyes is not particularly important and, since they can be transformed to become non-diffusible in the layers in the presence of the basic processing liquid and where they can themselves diffuse to the layers. the receiving product, they are; usable according to the invention.

   These developing dyes are particularly characterized by the fact that they contain a chromophore and at least one group, for example a hydro-quinonyl radical, which exhibits developing properties with regard to silver halides and which communicates to the molecule dye

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 The developer considered as a whole such a developing activity that, during the development of a silver halide image, the developing dyes are oxidized to less diffusible compounds in the exposed ranges where the development has taken place. Instead, the residual developer dyes, which are found in the undeveloped areas, are transferred to the etched receptor layers to form a color image therein.



  Of course, the developing dyes should not have any desensitizing action with respect to the silver halide emulsions.



   Typical developer dyes which can be used according to the invention are described in Australian patent 220,279, applied for January 31, 1957 and in German patent 1,036,640, applied for February 12, 1957, they are for example:
 EMI18.1
 4-Lp- (2 ', 5'-dihydroxyphenyl) -phenylaz ± 7-5-acetamido-1-naphtholr I Lp- (2', S'-dihydroxyphenétiyl) -phérylazo7-5-benzamido-1-naphthol. 1-Phenyl-3-methyl-4 -, p- (2 ', 5'-dihydroxyphenethyl) -phenylazs7-5-pyrazolone. 2-5- (2-1,51-dihydroxyphenethyl) -phenylaio7-4-acetamido-1-nai-lhtol. 2- / p- (Z>, 5 '-dihydroxyphenethyl) -phenylazo7-4 # amino-1-naphthol.

   2- / p- (2 ', 5' -dihydroxyphenethyl) -phenylazo7-4-methoxy-1-naphthol (magenta developing dye) 2 Lp- (2 ', 5'-dihydroxyphenethyl) -phenyla7 -!, - ethoxy -1-naphthol 2-p- (2 ', 5'-dihydroxyphenethyl) -phenylazQ7-4-n-propoxy-1.-narhtel (compound II) 1-phE; nyl-3-Nn-butyl-carboxamide- 4 p- (2 ', 5'-dihydro phenethyl) - (yellow developing dye) 1-pher-yl-3-.Nn-hexylcarboxamide-4 - p- (21,5'-dihydroxyhenethyl) - perylazô / - 5-pyrazolone (compound III 1-phenyl-3-carbethoxy-4- / p- (2 ', 5'-dihydroxyphenethyl) -phenylazo7- 5-pyrazolone 2 Lp- (2', 5'-dihydroxyphennétlyl) -phenylazç / -4-isopropoxy-1-naphthol 1-phenyl-3-.N-cyclohexylcarboxamido-4-, Cp- (2lj5l-dihydroxyphenethyl, -phenylaz / -5-pyrazolone. L-phenyl-3-phenyl-4- / p- (2 ', 5' -dihydroxyphenethyl) -phenylazo? -5-pyrazolone.

   2- (Lp- (2n, 6-dihydroxyphenethyl) -phenylazo7-alpha naphthylazo 4-methoxy-1-naphthol.

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 EMI19.1
 la -l-phenyl-J-amino-4- (4'-L2n, 5n-dihYdroXYPhenethyl) -phenylaz7 2 *, 5 '-diethpxyphenylazo) -5 -pyrazolone l-acetoxy-2¯ / p-beta-hydroquinonylethyl) -phenylazo7-4-methoxy-
 EMI19.2
 naphthalene
 EMI19.3
 4-isobutoxy-2- / p-beta-hydroquinonylethyl) -phenylaz.o7-l-naphthol l-aeetoxy-2- / p-beta-hydroquinonylethyl) -phenylazo7-4-propoxy
 EMI19.4
 naphthalene
 EMI19.5
 2 Lp- {2 ', 5'-dihydroxy-4'-methylphenethyl) -phenylaz7-4-propoxy-
 EMI19.6
 1-naphthol.

   
 EMI19.7
 1-phenyl-3 LN- (beta-ethylhexyl} -carboxyamide7-4 - {beta hydroquinonylethyl) -phenylazo, 5-pyrazoloné 1-phenyl-3- (Nn-heptyl) carboxyamido-4-Lp- (beta-hydroquinonyl - ethyl) -phenylazs / -3-pyrazolone lo-carboxyphenyl) -3-pb.ényl-4- / p- (2,5-trlfluoroacetoxy-beta-phenyl-ethyl) phenylazgY-3-hydroxy pyrazolone lactone. 1- (o-carbophenyl-3-N-phenylcarboxamide-.4 -beta'-hydroquinonyl-ethyl-phenylazo7 -5-hydroxypyrazolone lactone.
 EMI19.8
 



  Another class of developing dyes has been described in the aforementioned French patent 1,168,292. Examples of these dyes are:
 EMI19.9
 1,4-bis- (2 ', 5'-dihydroxyyanilino) -anthraquinone 1,5-bis- (2; 5> -dihydroxyanilino) -4, 8-dihydroxy-anthraquinone 1,4-bi s / beta - (3 ', W -dihydroxyphenyl) -ethylamino7-anthraquinone 1,4-bisLbêta- (2', 5'-dihydroxyphenyl) -isopropylamino7 -anthraqui-
 EMI19.10
 none (blue-green developer dye.)
 EMI19.11
 1,4- / beta- (2 *, 5 '-dihydroxyphenyl.) -ethylamino7-anthraquinone 1-chloro-4 Lbeta- (2', 5'-dihydroxyphenyl) -ethylamino7-anthraqui-
 EMI19.12
 none
 EMI19.13
 U-monobenzoyl-1,4-bis- / beta- (3 *, W -dihydroxyphenyl) -ethylamino7-
 EMI19.14
 anthraquinone
 EMI19.15
 N-monobenzoJl-1,4-bis Lbêta- (2 ', 5'-dihydroyphenyl) -ethyla:

  nino7-
 EMI19.16
 anthraquinone
 EMI19.17
 5,8-dhydroxy-1,4-bis Lbeta-hydroquinonyl-alpha-methvl} -ethylami.no / -anthraquinone (compound I) 1,4-bis- / (beta-hydroquinonyl-alpha-ethyl) -ethylainino7 -anthra-
 EMI19.18
 quinon e.
 EMI19.19
 5-hydroxy-1,4-bis- / ¯ (beta-hydroquinonyl-alpha-aethyl) -ethyl-
 EMI19.20
 amino7-an thraquinone
 EMI19.21
 1- (beta-hydroxy-alpha-ethylethylamino) -4- (beta-hydroquinonyl-alpha-methyl) -eth, lamino-anthraquinone, and 1- (butanol-2J -aiaino) -5,8-dihydroxy-4 -hydroquinonyl-isopropyl-
 EMI19.22
 amino-anthraquinone.

 <Desc / Clms Page number 20>

 



   Other developing dyes are described in Belgian patent 554,935, applied for February 12, 1957, British 804,971, 804,973, 904,974 and 804,975, all four filed on March 9, 1955 and French patent 1,168,292 cited above.



   It is also possible to use leuco-compounds, such as
 EMI20.1
 1-Phenyl-3-methyl-4- (2 '-m.ethyl-4' -diethylamino) -anilino-5-pyrazolone! which have no filtering action on the subjacent e.aulsion layers, which are immobilized in the developed regions, which diffuse towards the receptor product in the undeveloped areas @ @ and which oxidize there by forming color images.



   The developer dyes are present in one or more of the silver halide emulsion layers, or, preferably, in a hydrophilic organic colloid layer immediately adjacent to an emulsion layer, particularly under an emulsion layer. . Particularly satisfactory results are obtained when the developing dyes are present in the layer immediately below the emulsion layer, the spectral sensitivity of which is complementary to the color of the developing dyes. It is less advantageous to place the developing dye in a layer above the corresponding emulsion layer.

   The condition of contiguity of the developing dye and the silver halides can be satisfied by a "packet" system in which the developing dye is incorporated into a matrix embedding a particle or a globule containing grains of dye. 'silver halides.



   In multi-layered photographic elements, the order of superposition of the various layers of differently chromatized silver halide emulsion on the support may be different, i.e., reversed such that the layer sensitive
 EMI20.2
 , tbeud3 '.' 1. more. close to the support and the layer sensitive to the rou- \ p: ù: '1;: riiié' "In such arrangements of the layers, it is necessary: 8 'emulsions so as to prevent the en- tmâ - sarite- blue image in the emulsions esssmtiel- gstrer le rouge-.:at the green; for that,

 <Desc / Clms Page number 21>

 silver bromide emulsion can be used for the blue sensitive emulsion and silver chloride emulsions for the other emulsion layers.

   In these embodiments, it may be desirable to use the leuco compounds already indicated in place of one or more developer dyes which, since they may absorb somewhat in the blue, would tend to have undesirable filtering action on the strain of emulsion sensitive to blue located closest to the support.



   It is possible, to a certain extent, to modify the nature of the hydrophilic organic colloid constituting the binder of the emulsion layers, the overlays, the developer dye layers and the intermediate layers; it can be, for example, gelatin, gelatin compounds such as esters of dibasic acids, polyvinyl alcohol and cellulose aceto-monophthalate or mixtures of these substances. However, the best and most consistent results, and therefore the best quality prints, are obtained when gelatin is used as a binder for all layers of the photographic material.

   In fact, when gelatin intermediate layers are used, their thickness should be at least about three-quarters of the thickness of the yellow developer dye layer and they should contain a quantity of gelatin at least about twice the size. amount of gelatin in this same layer, so as to prevent diffusion of the developer dye and the developing products from layer to layer. Other hydrophilic organic collloids give poorer results in the layers.

   For example, when some of the layers contain gelatin as a binder and polyvinyl alcohol or cellulose acetomonophthalate intermediate layers are used, the layers tend to separate, especially when dry. when gelatin is used for all layers, a more uniform distribution of the basic treatment liquid and hydroquinone compound is obtained in the layers and dyes

 <Desc / Clms Page number 22>

 Developers forging the proof are more easily transferred to the receiving product.



   The processing liquid used to initiate the development of the exposed photographic material containing the developing dyes and hydroquinone compounds, and optionally the quaternary ammonium salt, should be strongly basic to accelerate the developing activity of the colo as much as possible. - developer rant. For this, it is advantageous to use, to constitute the activator, alkali metal hydroxides such as sodium hydroxide, or alkali metal salts such as sodium carbonate. However, it is also possible to use quaternary ammonium hydroxides or volatile amines, such as diethylamine, which have the advantage of evaporating and of not leaving any basic residue on the prints which tends to decompose the image. of dye.

   As already indicated, since hydroquinone compounds can be unstable in the strongly basic activator, it is preferable not to incorporate them into the treatment liquid, although when pyridinium salts are present this will be achieved. satisfactory results in other respects. Best results are obtained when the hydroquinone compound is present in the layers of the photographic material, so that no silver halide developer is required in the processing liquid. The basic treatment liquid can be replaced by water or by an aqueous solution of pH 7.5 or less, if the adjacent receiver sheet contains an alkali or an alkali releasing compound.

   If water or aqueous solutions become occluded in the photographic material or in the etched recipient material, they can be released by a suitable agent, such as pressure or heat *

 <Desc / Clms Page number 23>

 
The photographic elements according to the invention are, of course, suitable for the exposure customary in cameras. In addition, their development or the treatment with the basic liquid which triggers their development can also be done in the camera thanks to the use of frangible capsules to contain this liquid, or thanks to other devices. allowing this liquid to be uniformly spread over the exposed image or over a series of consecutive exposed images, in contact with the receiving product.

   For this purpose, it may be desirable to use a treatment liquid which contains, in addition to the strongly basic compound, a thickening agent, such as carboxymethylcellulose or high viscosity hydroxyethylcellulose, in an amount suitable to ensure. the desired viscosity. Other means, such as fine dispersion spraying, dipping, roll transfer, etc., can be used to apply the treatment liquid to the exposed product and initiate development therein.



   Thus, a series of consecutive images taken on a strip of the photographic material can be moistened with the processing liquid and the developer dye images can be transferred onto a single strip of the receiver material to obtain several color proofs in a single transfer operation. .



   One method of obtaining color proofs from a strip of photographic material containing a series of consecutive views, for example three or four, consists of applying a viscous processing liquid contained in a frangible or opening envelope, inside a compartment, such as a magazine, integral with the camera, as indicated below, so as to moisten each of the views with the treatment liquid, almost simultaneously, on contact of a strip of the receiving product and to transfer the corresponding polychrome images thereon to form a series of color proofs on a single sheet of the receiving product.

 <Desc / Clms Page number 24>

 



   Another method of obtaining prints from the photographic material bearing a series of consecutive views, for example three or four, is to expose this material in a conventional type camera, that is to say. - say not suitable for the use of frangible capsules to contain the treatment liquid, and to remove it from the device protected from light, by winding it on a reel of the usual type with protective backing paper or in a cartridge or magazine.

   The exposed photographic product is then introduced into a portable, light-tight box of small dimensions, so that it receives the processing liquid contained therein, for example, in a single frangible container or in a number of frangible containers equal to number of views exhibited, or applied by a wick, roller or equivalent device, so that each view exposed is wetted.

   As a result, the photographic material which bears several views exposed on the same strip containing differently chromatized emulsion layers and subtractive color-developing dyes contiguous with the silver halides of each emulsion layer is moistened with basic liquid in the presence of onium salts, and also in the presence of hydroquinone compounds, and brought into contact with the receiving product for a period sufficient for the correct development of each image, such that the silver halides of the various exposed areas of each emulsion layer are developed, and thus the corresponding developer dyes are immobilized therein,

   while the developing dyes of the unexposed plaques are transferred to the recipient product to form therein a series of tests consisting of the developing dyes.



   The cameras allowing, in addition to the exposure, the development and the transfer of an image on a receiving product inside the camera itself are well known and have been described, for example, in the patent of United States of America No. 2,435,717, requested October 6, 1945. Such devices are

 <Desc / Clms Page number 25>

 which can be used for the implementation of the invention.



   The receptor layers onto which the developing dyes are transferred to obtain the full color images can be composed of various products, such as linear polyamides, proteins such as gelatin, polyvinyl-pyrrolidone, poly-4-vinylpyridine, l polyvinyl alcohol, polyvinyl salicylal and methylcellulose. These receiving layers are applied to a suitable support such as paper, paper covered with a layer of polyethylene, a transparent film or a white pigmented cellulose ester support, to obtain a proof or a transparent plate as appropriate. .



   It may be desirable to incorporate a haze inhibitor into the photographic material, the basic processing liquid or the recipient material or each of these, as well as a development arrest compound to the recipient material. When development-arresting compounds are present in the receiving material, and not in the photographic material or in the processing liquid, they cannot work until they have been dissolved by the processing liquid and reached The photographic material in the course of development As a result, the latent image can develop very rapidly and the development is not significantly inhibited until the exposed areas are practically fully developed.

   This prevents development in the unexposed areas and increases the amount of developer dye carried over. Results are further improved when the development inhibitor agent is present in the receptor layer and the indicated quaternary salts are present in the treatment liquid or in the receptor layer or in both. Suitable development inhibitors are heterocyclic mercaptans, such as mercaptotetrasoles and mercaptobenzothiazoles, for example 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, etc.

   Many compounds which are commonly considered to be inhibitors

 <Desc / Clms Page number 26>

 haze for the silver halides do not sufficiently inhibit development in the process according to the invention.



   According to another embodiment of the invention, a small amount of a solvent for silver halides, such as a metal thiosulphate or thiocyanate, is incorporated into the basic treatment liquid or the receiving layer or both. alkaline or ammonium, which increases the general sensitivity of the process. The effect of this solvent is most marked when the hydroquinone compounds mentioned and / or the quaternary salts are present. Usually the amount of silver halide solvent used is not sufficient to determine the dissolution of an appreciable amount of silver halides in the unexposed and undeveloped areas of the photographic material and its transfer to the coating. receiver.



   The invention extends to photographic products whose
 EMI26.1
 the support is suitable for receiving the developer-colorant images and is of such a nature that it can be separated from the sensitive layers or is separated from these layers by a layer facilitating the release. The basic liquid can be supplied as already indicated or, if the alkali is contained in one of the layers, the liquid can be water.



   The silver halide emulsions which can be used according to the invention include the known silver halides and their mixtures, for example, silver bromide, silver bromoiodide or silver chlorobromide.



   The emulsion adjuvants described in Belgian patent 578,470 applied for on May 6, 1959 as well as in French patent 1,205,155, applied for on July 29, 1957 and comprising salts of noble metals, stannous salts, polyamines, optical sensitizing dyes, mercury compounds, sensitivity enhancing compounds such as quaternary ammonium salts and polyethylene glycols, plasticizers, tanning agents, coating aids and colloidal binders can be used beforehand.

 <Desc / Clms Page number 27>

 carefully in the silver halide emulsion layers of sensitive products according to the invention.



   The following non-limiting example illustrates the invention.



    EXAMPLE. -
A sensitive product is prepared by applying the following gelatin layers, suitably tanned, to a substrate film substrate, as follows.



   An aqueous gelatin solution containing the blue-green developing dye (compound I) dissolved in a mixture of Nn-butylacetanilide, 4-methylcyclohexanone and the dispersing agent Alkanol B is prepared, and is passed through a mixture several times. colloid mill, layer and dry the resulting layer to volatilize 4-methylcyclohexanone.



   A layer of red-sensitized gelatin-silver bromoiodide emulsion containing 4 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetraazaindene per mole of halide is applied. silver on the blue-green developer dye layer.



   An interlayer of gelatin is then applied.



   Then apply an aqueous gelatin solution containing the magenta developing dye (compound II) dissolved in a mixture of cyclohexanone, Nn-butylacetanilide and Alkanol B, it is passed several times through a colloidal mill, it is coated over the previous interlayer and the resulting layer is dried to volatilize the cyclohexanone.



   A green-sensitive emulsion also containing 4 g of the above azaindene per mole of silver halide is then coated on the layer of magenta developing dye.



   A second interlayer of gelatin is then applied.



   An aqueous gelatin solution containing the yellow developing dye (compound III) dissolved in a mixture of ditetrahydrofurfuryl adipate, ethylene glycol monobenzyl ether and Alkanol B is then prepared, it is passed several times through a colloidal mixture. , the dispersion obtained is cooled in order to gel it, it is washed to remove the monobenzyl ether of

 <Desc / Clms Page number 28>

   ethylene glycol and applied to the second interlayer and dried.



   A layer of silver bromoiodide emulsion sensitive to blue and containing the aforementioned quantity of azaindene is then applied to the layer of yellow developing dye.
 EMI28.1
 



  The dispersion D-ldtmcl3ivé of myczroquinone PART A.
 EMI28.2
 4'-methylphenylhydroquinone .................. 136 g
Methyl alcohol ............................ 136 ml
Di-n-Butyl phthalate ..................... 272 ml
Heat to 70 C to dissolve the mixture, then cool to 40 C.



   PART B.



   Gelatin solution of 10 1360 g
Water ......................................... 1360 ml
5% aqueous solution of Alkanol B ........... 136 ml
This mixture is heated to 40 ° C. Part A is then slowly added to part B with mechanical stirring. The resulting solution is then passed five times through a Manton-Gaulin laboratory colloid mill. The colloidal mill is rinsed, the dispersion is made up to 3775 g, it is gelled by cooling and it is stored in a refrigerator:
The following coating composition is then prepared.



   PART I.



   Dispersion D-l ............................. 3.775 g
Water ......................................... 2.227 ml
The mixture is heated to 4.0 C.



   PART II
10% gelatin solution 3.180 g
Water ....................................... 12,000 ml
2.5% aqueous solution of mucochloric acid ..................................... 515 ml
Heated to 40 ° C. and the pH is adjusted to 5.5.

 <Desc / Clms Page number 29>

 



   The parts I and II are then combined and diluted to 22,700 ml with water. This solution is coated on the blue sensitive layer to obtain about 1280 mg of gelatin per square meter and 428 g of 4'-methylphenylhydroquinone per square meter.



   We expose a sample film obtained from lying beech (designated by the n 4894) under a sensitometric wedge, behind red, green and blue filters, and we moisten it with the activator of the following composition, while it is at contact of the receiving sheet indicated below. As a result, the blue-green, magenta and yellow developing dye images are transferred from the undeveloped areas onto the receiver sheet. After about two minutes, the receiver sheet containing the developer dye images was separated and the densities of these images were measured in the usual way using red, green and blue filters.



   ACTIVATOR
It is constituted by a solution containing 3.5% of hydro-xyethylcellulose (Hercules type 250 product, high viscosity), 4.5% of soda, 2.0% of benzotriazole and 2.0% of 1-phnethyl bromide. -2-picolinium.



   RECEIVING SHEET
It consists of a cellulose ester support pigmented in white, carrying a gelatin layer containing a mixture of poly-4-vinylpyridine as mordant and 1-phenyl-5-mercaptotetrazole.



   Further samples of Film # 4894 were baked for seven days at 50 ° C and 50% relative humidity. They were exposed and processed as above to obtain developer dye images having good density.



   A control film # 4893 is prepared in the same way as film # 4894, except that azaindene is not put in the emulsions. We treat samples of this control film as

 <Desc / Clms Page number 30>

 described above, before baking and after baking for seven days.



   The relative densities of the images of the 4893 film and of the 4894 film before and after baking are shown in the following table.



   BOARD.



  N of the film Density before baking Density after baking
Blue-green Magenta Yellow Blue-green Magenta Yellow 4893 1.64 1.51 1.50 1.02 0.78 1.18
4894 1.66 1.62 1.61 1.68 1.65 1.65
From these results, it appears that the 4894 azaindene film according to the invention gives blue-green, magenta and yellow images of approximately the same density before and after baking, while the film Control 4893 not containing azaindene gives blue-green, magenta and yellow images showing markedly lower densities after baking.



   In the same way as in the previous example, 4 g of 4-hydroxy-6-methyl-1,2,3,3a, 7-pentaazaindene are added respectively per mole of silver halide and 4 g of 2, 4-dihydroxy-6-methyl-1,3a, 7-triazaindene per mole of silver halide to emulsions of two analogs containing green-sensitive gelatin-silver bromoiodide emulsion layers and colorant layers underlying developer. After baking the two products under the same conditions, the tests obtained from these products show a smaller loss in density than the control product which did not contain azaindene.



   The other triazaindenes, tetraazaindenes and pentaazaindenes can be used in the same way in emulsion layers.



  It may be desirable in some cases to use various amounts and types of azaindenes in the respective emulsion layers of a multilayer film.



   The uniformity of coating carried out as described above is greatly increased by adding an anionic surfactant, such as an alkylarylsulfonate, for example, sodium triisopropylnaphthalenesulfonate (Alkanol B) to the layers.

 <Desc / Clms Page number 31>

 developer dye, and whether the silver halide emulsions applied to those developer dye layers contain a cationic surfactant, such as laurylpyridinium para-toluenesulfonate. The unique effect of azaindenes may result from action on developing dyes or other components of the system.


    

Claims (1)

Of course, the invention is not limited to the embodiments described, which have been chosen only as examples - SUMMARY. The objects of the invention are in particular 1 - An inversion-transfer process in colors remarkable in particular by the following characteristics, considered separately or in combinations a) a photographic product comprising a support, on which are applied, in superposition, several layers of 'silver halide emulsion of different chromatic sensitivities, at least one of the emulsion layers containing a hydroxylated or amine tri-, tetra- or pentaazaindene, a developing dye being adjacent to the silver halides of each emulsion layer, said developing colorant being a compound which is at the same time a silver halide developer and a colorant, the photographic product is applied under pressure in contact with an etched receiving layer in the presence of a layer of an alkaline solution placed between the emulsion layers and the receiving layer, to develop the silver halides and render the developing dye non diffusible in the exposed and developed areas, the developing dyes of the unexposed areas are allowed to diffuse imagewise and register on the receiving layer, and the receiving layer is separated to obtain thereon a polychrome image composed of the developing dyes; b) the product indicated under 1 a) contains, in addition, a <Desc / Clms Page number 32> hydroquinone practically colorless and practically insoluble in water, but soluble and diffusible in alkaline solution, placed in a layer on the support; c) a quaternary ammonium salt is present when the emulsion layers are brought into contact with the receiving layer; d) the emulsion layers of the product indicated in 1 a) are respectively sensitive to red, green and blue and the developing dyes are of complementary colors and are present in a non-photosensitive layer placed under each emulsion layer; 2 - A remarkable photographic product, in particular for the following characteristics, considered separately or in combination: a) it comprises a support, on which are applied, in superposition, several layers of silver halide emulsion of different chromatic sensitivities, at least one of the emulsion layers containing a tri-, a tetra- or a penta- hydroxylated or aminated azaindene, a developing dye being adjacent to the silver halides of each emulsion layer, said developing dye being a compound which is at the same time a silver halide developer and a dye; b) the product additionally contains a substantially colorless hydroquinone which is practically insoluble in water, but diffusible in alkaline solution and placed in a layer on the support.