BE607421A - - Google Patents

Description

       

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  New color inversion-transfer process and receiver product usable in this process.



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



   A process of this type has been described, for example, in French patent 1,168,292, applied for on December 29, 1956. As indicated in that patent, a photographic material is used comprising layers of halide emulsion. silver and layers containing diffusible "coloring developers", these coloring developers which will be called hereinafter developer dyes:

   being) constituted by dyes whose molecule contains a 'developing group for the silver halides, these products are exposed

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 so as to form a latent image in the silver halide emulsions and are treated with a basic processing liquid which diffuses into the emulsion layers and into the layers containing the developing dyes, these converting then the latent images in silver images. Simultaneously, 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 failure of the oxidized developer dyes to diffuse is apparently due, at least in part, to a reduction in the solubility in the basic processing liquid and, possibly also, to a tanning or hardening action of the oxidized developer * on the material. colloid constituting the binder of the layers, action having the effect of slowing down the diffusion of oxidized developing dyes. The unoxidized dye developers which remain in the layers following an image-dependent topographic distribution are transferred by diffusion onto a receiving product superimposed on the photographic product, to the practically total exclusion of the silver image and of the dye. oxidized developer, to form an image of positive dye in the recipient product.



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



   It is evident that the success of the process depends in part on the efficiency of the process by which the dyes develop.

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 Loppers of exposed (negative) regions of emulsion layers become non-diffusible during development.



  Thus, if there remains in a negative region exposed to the maximum, that is to say corresponding to the great lights of the subject, a certain quantity of non-oxidized developing dye, the latter is transferred to the product. receptor together with the positive region developing dye, so that the minimum density of the color proof is relatively large.



  Characteristic developer dyes, such as 1,4-bis
 EMI3.1
 eta- (2, 5-dih; droxy'phénYl) -étt'lamino> -, anthraquinone of formula
 EMI3.2
 are relatively weak developers for silver halides, even when used at the high pH value which is necessary for carrying out the process, i.e. at a pH value of about 13, and fail to develop a silver halide emulsion quickly enough to fully take advantage of the known sensitometric properties of emulsions and to provide images of dyes which exhibit the same extreme density range and contrast as those found. one can discount when using other developers.

   As a result, the color proofs obtained by this process often show an exaggerated minimum density in the regions of the image which correspond to the high lights of the original, saturation, poor color, limited contrast, low density. and poor color separation. These effects are partly due to the ineffectiveness of developing dyes in

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 as silver halide developers, to the lack of discrimination of these developing dyes for the silver halides they must develop, as well as other factors.



   An improvement has been made by the use of a colorless auxiliary developer, for example, 1-phenyl-3-pyrazolidone, in the treatment liquid, the effect of this developer being an acceleration of the development of the halides of. silver and immobilization of the developing dye in the photographic material. However, satisfactory polychromatic proofs are not yet obtained in this manner, particularly because the basic processing liquid which contains the auxiliary developer does not yet allow development to proceed in such a way that the various developer dyes necessary for a polychrome system are each immobilized in the desired layer and in the desired time and measure.



   The aforementioned French patent, as well as other patents whose reference is given below, relates to various. characteristics of the basic process which uses developing dyes for the formation of color images by inversion transfer and indicates how the process is to be carried out with these developing dyes to obtain monochromatic images and how the same principles are applicable to obtaining full color images.

   However, it has been found that while photographic elements containing several layers of differently chromatized silver halide emulsion and adjacent developing dyes and adjacent developing dyes can be used for obtaining full-color subtractive color images. which arise for this application of the method to obtaining polychrome images are very different from those which arise with respect to obtaining monochrome images and that, consequently, the solutions are also very different.

   For example, the development products of one of the emulsions may alter the development of the other emulsions, the diffusion of a developing dye may be hindered or prevented by a developing dye or another.

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 substance which is in a layer which must necessarily pass through the first developing dye, the depletion of the processing liquid in the outer layer may alter the development of an inner layer so that one of the emulsion layers may not be developed to the same degree as another emulsion layer, and, in particular, it may happen that a developing dye is not immobilized enough not to be transferred and not create parasitic coloring in a color image. - rant of another color.

   In addition, a given developer dye may develop a few silver halide grains in an emulsion layer other than the one on which it is to act, so that the amount of developer dye that remains available is ble for the transfer is insufficient and the corresponding colors are not sufficiently saturated; for example, a developing magenta dye can accidentally develop a few grains of the red-sensitive emulsion layer and become immobilized in this layer, which limits the amount of magenta available for red colors which then lack color. saturation.



  The method according to the invention is such that this action or this reciprocal dependence of the various layers, the various developing dyes and the various other agents which form part of a photographic product with several emulsion layers, is suppressed or compensated, so that polychrome images of a higher quality are obtained than the polychrome images which have heretofore been obtained by the inversion-transfer process.



   According to the invention, it has been found that the quality of color proofs can be considerably improved when certain hydroquinone derivatives are present in one of the layers of the sensitive product containing developing dyes, since apparently each of the developing dyes of the various layers is more completely and more evenly immobilized and the color contamination of the dye images is reduced.

   Although a noticeable improvement in color quality is obtained, it appears that the developer dyes have not yet been

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 immobilized in the exposed ranges, at the required speed, in the desired degree and in the appropriate layer *
It has been found that when sensitive products containing developing dyes and hydroquinone derivatives are treated in the presence of at least one diffusible onium compound in the layers in alkaline solution, the contamination of the colors is considerably reduced, and if the onium compound used is a heterocyclic compound forming a methylene base diffusible in the layers in alkaline solution, not only the contamination of the colors is greatly reduced, but the developing dyes are immobilized in the appropriate layers,

   with the additional result that the colors of the images are much more saturated.



  Thus, all onium compounds are effective in improving the color quality of proofs in some respects, but not necessarily the same.



   According to the invention, the color inversion-transfer process is carried out using developing dyes with multilayer sensitive products containing developing dyes and certain hydroquinone derivatives, and in an adjoining position. , practically colorless onium compounds diffuse in alkaline solution into the organic colloidal layers of sensitive products. For example, the ternary sulfonium, quaternary phosphonium and, particularly, quaternary ammonium salts and, preferably, certain heterocyclic quaternary ammonium salts are diffusible in alkaline solution in the organic layers of the sensitive products.

   One or more types of onium compounds may be present in the alkaline treatment composition, in the recipient product or in the photosensitive product containing the developing dyes.



   As a result, color contamination is reduced and color saturation is improved as well as other characteristics of the process. In other words, hydroquinone derivatives and all onium compounds are effective in improving

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 improve the color quality of proofs in some respects but not necessarily in the same. In particular, the preferred heterocyclic quaternary ammonium salts reduce "color contamination", "loss of saturation" as well as minimum print density.

   Color contamination usually appears in proofs as a denaturation of one or more colors by one or more other colors and may be due to one or more developing dyes not sufficiently immobilizing and being transferred from beaches where they should have been immobilized. The loss of saturation appears as a defect in the color quality of the proofs which is apparently due to the fact that a developing dye has developed grains of silver halides in an emulsion layer on which it would not have. This should not have acted, for example, because the magenta dye has developed red-sensitive silver halide grains and there is therefore too much magenta dye immobilized so that the reds thus lack magenta.

   The action between the onium compounds and the hydroquinone derivatives is particularly evident, when the organic colloidal binder of the sensitive product containing the developing dye consists mainly of gelatin. Many of the common optical sensitizing dyes are conjugated quaternary ammonium salts, but they are not ordinarily usable in place of colorless quaternary ammonium salts, particularly because they are not sufficiently soluble and diffuse and cause parasitic coloring of the prints.



   The objects of the invention are therefore in particular - A photographic product comprising several superimposed silver halide emulsion layers of different sensitivities and containing developing dyes in contiguous position and hydroquinone derivatives, - A process for treating said products in presence of quaternary ammonium salts, - sensitive products, treatment compositions and receptor products particularly suitable for taking

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 of views in a camera, the processing of these products being done in the apparatus.



  The characteristics of the present invention will become apparent from the following description of a photographic product * = taking several layers of halide emulsions.
 EMI8.1
 'tereat differently chro8atiÁ .. (sensitive to different regions of the spectrum) containing adjoining developing dyes which may be of complementary colors to those
 EMI8.2
 which the corresponding layers of water are sensitive, and hydroquinone derivatives also in contiguous position @., and, of a treatment process which consists in treating the product with an alkaline treatment solution easy in contact with the receiving layer and in contiguous position of onium compounds and particularly quaternary ammonium salts,

   to develop the exposed silver halides of the emulsion layers and thereby render the developing dyes non-diffusible in the regions where development takes place, and to allow the developing dyes of the undeveloped regions to be carried over following a pattern. distribution corresponding to the positive image, by diffusion and registration, on the receiving support where they form a polychrome image of developing dyes.



   In the accompanying drawing, given only by way of example, - FIG. 1 comprises a schematic section of the photographic material and of the receptor material superimposed on this photographic material, with the interposition of the treatment liquid, and, at the lower part of the figure, a section of the receptor product after the transfer of the color developers; - Fig. 2 is a schematic sectional view of another embodiment of the photographic element; - Fig. 3 is a schematic representation of the implementation of the method.



   As indicated by the upper section of FIG. 1, the
 EMI8.3
 photographic material used in accordance with 1nVention.comincludes.; -

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 support 10, layers 1,1 12 and 13 containing respectively blue-green, magenta and yellow developing dyes, soluble in basic medium, silver halide emulsion layers 14, 15 and 16 respectively sensitive to red. , in green and blue, intermediate layers 17 and 18 which separate the green sensitive emulsion layer and the adjacent magenta developing dye layer from the other layers and an overlayer 19 containing one of the following hydroquinone derivatives invention.

   The receiving product which comprises a support 20 and a receiving layer 21 (which may contain the onium compound) is placed relative to the photographic product so as to receive the images of dyes which diffuse therein from the photographic product. , a frangible sachet containing the basic treatment liquid 22 with pyridinium salt.

   When the bag 22 opens, for example due to the passage of the assembly between the rollers of the camera and the contents thereof are spread uniformly over a defined area, the photographic product, the processing liquid penetrates into layer 19 where it dissolves the hydroquinone compound insoluble in water, but soluble and diffusible in basic medium, and entrains this compound in the subjacent layers to convert there the latent images formed by the silver halides in. The regions 23, 24 and 25 in silver images, while the developing dyes which are in the regions contiguous to the regions 23, 24 and 25 are immobilized and made non-diffusible.



  The developing dyes located in the layers 11, 12 and 13 and which have not reacted then diffuse in a distribution which corresponds to the positive image and in registration up to the receiving layer 21 to form dye images therein. .



   According to the embodiment shown in FIG. 2, the developer dyes are incorporated into the differently chromatized emulsion layers 31, 32 and 33 and the hydroquinone compound is in the outer layer 34.



  In Fig. 3, there is shown a device sealed against

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 light which is useful for processing a reel of exposed film containing silver halide emulsions and developing dyes, and wherein the film is wetted with an alkaline activator solution and contacted with a re-foil. - etched strainer to transfer multiple developer dye images to this sheet *
It is believed that the onium compounds react with the developing dyes to form salts and that the improvements obtained particularly in density and highlights are due at least in part to the effect of the formation of these. salts on the solubility and diffusibility of developing dyes.

   It is evident that the onium compounds temporarily retard the diffusion of the developing dyes, so that the initial diffusion rates of the developing dyes are reduced and, however, more of the developing dyes diffuse less exposed areas to increase. the density.



   Onium compounds have been used for some time for phtoography. For example, quaternary ammonium compounds without surface activity have been used as development accelerators. French Patents Nos. 949,227, 949,228 and 949,229, all applied for on August 11, 1945, describe the use of quaternary ammonium compounds, quaternary ammonium compounds and ternary sulfonium compounds as sensitizers for halide emulsions. silver. 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 ranges of the negative and can be attributed to the above stated ability of the onium compounds to sensitize an emulsion or accelerate development.

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 is lying. On the contrary in the processes to which the present invention relates, when there is an increase in density, this takes place in the positive image and is essentially due to the fact that a greater quantity of dye developed their density. was transferred from unexposed regions to the negative.

   The fact that the onium compounds 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 color accelerators. development. In addition, the improvements obtained in the implementation of the inversion-transfer processes to which the invention relates are not necessarily linked to an increase in surface activity due to the presence of the onium compounds, since the compounds onium which generally result in the greatest increase in density cannot generally be considered to have surface activity.

   The increase in density is believed to be at least partially due to the ability of onium compounds to increase the solubility of developing dyes.



   The fact that 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 match the big 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. It is known that quaternary ammonium compounds are organic compounds which contain a pentavalent nitrogen atom. In general, they can be considered to derive from ammonium compounds in which the four valences generally satisfied by the hydro atoms.

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 gene are satisfied by organic radicals. In general, organic radicals are linked directly to pentavalent nitrogen through a single or double carbon-nitrogen bond.

   In this specification, the term quaternary ammonium covers compounds where pentavalent nitrogen is one of the nuclear atoms of a heterocyclic ring, as well as compounds where the four valences are satisfied by separate organic radicals, such as example, as is the case with the tetraalkylated quaternary ammonium compounds. Examples of quaternary ammonium compounds are conati killed by compounds which can be represented by the following formulas
 EMI12.1
 where R represents an organic radical, Y an anion, for example a hydroxyl or toluenesulphonate group, a bromine or chlorine atom, etc. and Z the atoms necessary to complete a heterocyclic ring.

   Specific examples of compounds corresponding to the for-
 EMI12.2
 mules I, II and III are tetraethylam-onium bromide, N-ethylpyridinium bromide, N, N-ethylpyridinium bromide, ethylene-bis-pipéridinium bromide, 1-ethylpyridinium bromide, 1-pher * .Z - 3-picolinium bromide, tetraalkylammonium salts, cetyltrimethylammonium bromide, polyalkylene oxides with two quaternary ammonium salt functions, such as bis-pyridinium-perchlorate of polyethylene oxide, ammonium salts

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 mentioned heterocyclic quaternary nium which form methine bases such as 3-methyl-2-ethylisoquinolinium bromide, 3-methylisoquinoli- methyl paratoluenesulfonate
 EMI13.1
 nium,

   1-ethyl-2-methyl-3-phenethylbenzimidazolium bromide, 5,6-dichloro-1-ethyl-2-ethyl-3- (3-su3.fobutyl) -benzimidazolium betalne and the pyridinium salts indicated above -after.



   The ternary sulfonium and quaternary phosphonium compounds can be represented respectively by the formulas (IV) (R) 3 S + X- (V) (R) 4 p + X- where R represents an organic radical, for example an alkyl group , aralkyl, aryl, etc., and X an anion such as a hydroxyl or toluene sulfonate group, a bromine or chlorine atom etc.

   Examples of ternary sulfonium and quaternary phosphonium compounds are lauryldimethylsulfonium p-toluenesulfonate, nonyldimethylsulfonium para-toluenesulfonate and octyldimethylsulfonium p-toluenesulfonate, butyldimethylsulfonium bromide, triethylsulfonium bromide , tetraethylphosphonium bromide, dimethylsulfonium paratoluenesulfonate, dodecyldimethylsulfonium para-toluenesulfonate, decyldimethylsulfonium paratoluenesulfonate and ethylene-bis-oxymethyltriethylphosphonium bromide.



   The oniun compounds can be used in the form of hydroxides or in the form of salts. 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, as this anion has harmful effects on the emulsion.



  Particularly satisfactory results are obtained when the onium compounds are used in the bromide state.



   The particularly effective heterocyclic quaternary ammonium compounds which form the diffusible methylene bases in basic solution correspond to the general formula

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 EMI14.1
 where D represents the metal 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 bearing substituents or not, such as a nucleus of the series of pyridine, quinoline, benzoquinoline, benzoxazole, benzoselenazole, thiazole, benzothiazole, naphthothiazole, benzimidazole, isoquinoline, etc., n being 0 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 to 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 Br-, CH3SO4 or CH3 -SO3. One or more of these quaternary ammonium compounds can be used, alone or in combination with onium compounds of formulas I, II, III, IV and V and, advantageously, they are incorporated into the treatment liquid, the receiving product or the product. to both, or less advantageously to the photographic material, their presence improving the quality of the print by a poorly understood process. 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 color proofs obtained show much less color contamination, as well as better color saturation, density and contrast.



   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 the proportion between 2/1000 and 150/1000. In some cases, a proportion between 2/1000 and 30/1000 is preferable. Likewise,

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 when incorporated into the photographic material or the receptor material, the amount of onium compound to be used varies depending on the nature of that 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 the formula (VI), the pyridinium nucleus bearing in at least one of the 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. Positions 3 and 5 may or may not bear 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: 1-Benzyl-2-picolinium bromide 1- (3-bromopropyl) .- 2-picolinium p-toluenesulfonate 1-Phenethyl-2-picolinium bromide 1- (3-bromopropyl) bromide gamma-phenylpropyl-2-picolinium 2,4-dimethyl-1-phenethylpyridinium bromide 2,6-dimethyl-1-phenethylpyridinium bromide 5-ethyl-2-methyl-1-phenethylpyridinium bromide 2-ethyl-1- bromide phenethylpyridinium
 EMI15.1
 1 -, - (H-bromopyridinium) -propy-2-picolinium p-toluenesulfonate
 EMI15.2
 

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 EMI16.1
 Anhydro-l - ((4-aulfobutyl) hydroxide

  -2-picoliniua
 EMI16.2
 Alpha-picolin-beta-naphthoyl kethylbromide
 EMI16.3
 
 EMI16.4
 1-beta-pherylcarbamoyloretyl-2-picolinium bromide
 EMI16.5
 l-methyl-2-picolinium p-toluenesulfonate
 EMI16.6
 1-Phenethyl-2,4,6-trimethylpyridinima bromide 1-Phenethyl-4-n-propylpyridinium bromide 4-gamma-hydroxypropyl-1-phenethylpyridinium bromide
 EMI16.7
 1-n-heptyl-2-picolinium bromide
A certain number of pyridinium salts of the general formula indicated above do not form methylene bases sufficiently diffusible in a basic medium to be of any use in the process according to the invention. These are, for example, the bromuressde
 EMI16.8
 l-n-decyl-2-picolinium, 1,2-dibenzyl-pyridinium.,

   of 6-amino-1-phenethyl-2-picolinium, of 2-amino-1-phenethyl-4-picolinium., of 2-benzYl-1-phenethylpyridinium and of 4-benzyl-1-phenethylpyridinium.

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  The bromides of 1-phenethylpyridinium, 1-ethyl-
 EMI17.1
 pyridinium, and 1-phenethyl-3-picollnium and 1-n-xlonylyridiniuae 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
 EMI17.2
 2'-Hydroxyphenylhydroquinone Phenoxyhydroquinone 4-1-methylphenylhydroquinone 1,4-dihydroxynaphthalene 2- (A-aainophenethyl) -5-bromohydroquinone 2- (l, -aminophenethyl) -5-methylhydroquinone 4'-aminophenetayquinone-2-hydroquinone 5-dibutx> xyhydroquinone m-xylohydroquinone Bromohydroquinone 3,6-dichlorohydroquinone
 EMI17.3
 2-dimethylaminoétiyltoluh, ydroquinone 2-cyclohexylhydroquinone Sec.butylhydroquinone 2,5-dichlorohydroquinone
 EMI17.4
 z, 5-düsopropylhydroquinone 2,5-diiodohydroquinone 3-chlorotoluhydroquinone Tetrachlorohydroquinone 2,5-diphenylhydroquinone
 EMI17.5
 2,5-dresorcylhydroquinone 2,

   5-d.octy7.idroquinone Dodecylhydroquinone

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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.



   The process according to the invention is carried out with silver halide emulsions and developing dyes in contiguous position with quaternary ammonium salts and hydroquinone derivatives. In other words, the quaternary salt can be present in the alkaline processing liquid and / or in the receptor sheet, and less advantageously in the sensitive product, while the hydroquinone derivative can be in one of the layers of the product. sensitive, such as an overcoat, an emulsion layer, a developer dye layer, an interlayer or in the receiver sheet. Thus, the receiver sheet or the receiver layer may be composed of a mordant for the developing dye as mentioned below, for example poly-4-vinyl-pyridinge and may also contain at least one of the hydroquinone derivatives. above.

   Likewise, the receiving layer or the sheet may contain the combination of a mordant for developing dyes, at least one of the hydroquinone derivatives and at least one of the aforementioned onium compounds, particularly the heterocyclic quaternary ammonium compounds. forming methylene bases. For some purposes, the hydroquinone derivatives may be present in the processing liquid.



  However, in the process of the invention, the use of these derivatives in this liquid is much less advantageous, since these derivatives are unstable in such solutions and easily undergo oxidation accompanied by discoloration of the prints, unless prepare these and store them in the absence of air or take other precautions to avoid oxidation.



   The hydroquinone compounds used, as described above, are preferably incorporated in the emulsion layers, in the overcoat, in the intermediate layers or in other layers, in the form of a dispersion in the colloidal binder. organi-

 <Desc / Clms Page number 19>

 that hydrophilic layer. The hydroquinone derivatives can also be dissolved in alkaline solutions and precipitated in aqueous gelatin solutions, increasing the acidity of the solution. However, this procedure is advantageous because of the instability of the compounds in alkaline solution. The hydroquinone derivatives can be dissolved in a solvent, such as a lower alcohol, and precipitated in the aqueous gelatin solutions for coating on the sensitive product.

   They can also be added to gelatin solutions which are then passed through a ball mill to reduce the size of the crystals. However, the hydroquinone derivatives are preferably dissolved in a crystallol-dal solvent permeable to alkaline processing solutions and having a boiling point above about 175 ° C., such as dibutyl phthalate, and added to a solution. aqueous gelatin which is then passed through a colloid mill until the desired degree of subdivision is reached. An auxiliary organic solvent can also be used, such as a solvent having a solubility in water greater than that of the crystalline solvent and which is at least equal to about two parts per hundred parts of water.



  Thus, the auxiliary organic solvent can be washed away from a gelatin gelatin dispersion in the presence of the following other.



  The auxiliary solvent may be a solvent having a boiling point at least about 25 ° C lower than that of the crystalloidal solvent, so that it can be removed by volatilization during drying. one layer, to leave the hydroquinone derivative dispersed only in the crystalline solvent. As a result, the hydroquinone derivatives are rapidly and uniformly dissolved in the alkaline treatment composition and thus incorporated throughout the sensitive product to produce more uniform development than when the hydroquinone derivatives are incorporated into the products. by any other means.



   Hydroquinone derivatives can be used in one or more layers of the sensitive product and in amounts of

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 around 107-1070 mg or more per square meter. However, the amount used depends in part on the amount of silver halide, the layer in which it is incorporated, the amount of developing dye and the amount of pyridinium salt in the sensitive product or in the substance. treatment solution for the receiving product. In some cases it may be desirable to form a complex of the hydroquinone derivatives by reaction with sulfur dioxide in a known manner and to incorporate the complex into the overcoat, into the outer emulsion layer or into the outer emulsion layer. another layer of the sensitive product.

   These hydroquinone and sulfur dioxide complexes tend to be 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 to be so in the presence of basic processing liquids. In the majority of cases, the developing dyes are insoluble in water, which usually necessitates the use of organic solvents to incorporate them into the colloid layers of photographic elements.

   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 environment. receiving product, they can be used 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 hydroquinonyl radical, which exhibits developing properties with regard to silver halides and which communicates to the molecule of the substance. developing dye considered as a whole a developing activity such as, during the development of an image

 <Desc / Clms Page number 21>

 of silver halides, the developer dyes are converted by oxidation to less diffusible compounds in the exposed areas where development takes place, the residual developer dyes, which are in the undeveloped areas, being carried over to the etched receptor layers to form a color image.

   Of course, the developer dyes should not have any desensitizing action against the silver halide emulsions.



   Characteristic developing dyes which can be used in the photographic elements according to the invention have the general formula
M - N = N - D where M is an aromatic or heterocyclic ring (or ring system), such as a benzene, naphthalene, tetralin, anthracene, anthraquinone, pyrazole, quinoline ring, etc., which ring can carry substituents, such as hydroxyl, amino, keto, nitro, alcozy, aryloxy, acyl, alkylamidon arylamido, alkyl, aryl, carboxamido, sulfonamido, carboxyl or sulfo groups, and D represents a developing dye communicating moiety developing properties of silver halides, for example a hydroquinonyl radical which may bear amino, alkylamino, alkyl or hydroxyl groups or atoms,

   alkoxyl or halogen.



   A very useful class of developer dyes, described in Australian Patent 220,279 issued January 31, 1957 and German Patent 1,036,640 dated February 12, 1957 correspond to general formulas.
 EMI21.1
 
<tb> -Y-R-Ar-N = N- <SEP> Q <SEP> Y-Ar-N = N- <SEP> Q
<tb>
<tb> P <SEP> P
<tb>
 where p = 1 or 2, R is an alkylene group containing from one to five carbon atoms, Ar an aryl group from the benzene or naphthalene series, Z is a lower alkyl group, such as methyl or ethyl, or a

 <Desc / Clms Page number 22>

 
 EMI22.1
 halogen atom, such as chlorine, Z 'a lower alkoxyl group, ¯ such as methoxy or ethoxy, a halogen atom or an alkyl group
 EMI22.2
 lower, m = 0.1 or 2, Y is a 2,5- or 2,3- or 3,4- group
 EMI22.3
 dihydroxyphenyl which may bear alkyl groups or hydrogen atoms,

   Q the remainder of a coupler, such as a coupler of the phenolic, naphtholic, 5-pyrazolone or methylene groups reactive with
 EMI22.4
 open chain containing the group -CO-CR2-CO. Examples are 4 - ZP¯ (2'5 * -dihyâroxyphenyl) -phenylazo7-5-acetamido-1-xiaphthol, lp- (2'S'-dihydrovphenethyl) -phenylazg, -5-benzamido-1-naphthol, 1-Phenyl (-3-methyl -, - p- (2 ', 5' -dihydroxyphenethyl) -phenylaz-5- pyrazolone, 2-p- (2 ', 5'-dihydroxyphenethyl) -phenylaz-4- acetamid-1-naphthol, 2 Lp-2 ', 5'-dihydroxyphenethyl) -phenylazc7 -.- amino - 1-naphthol, 2', 5'-dihydrophenet3.y1) -phenylaz> -4-methoxy- 1- Naphthol (magenta developer dye), 2 p- (2 ', 5'-dihydroy-phenethyl) -phenylazQ7-4-ethoxy-1-naphthol, 2- / ¯-p- (2', 5'- dihydroxy-phenethyl) -phenylazp7-4 - n-propoxy-1-naphthol (compound II), 1-phenyl-3-Nn-butylcarbox, amido-4- ± --p- (21,

  5'-dihydroxyphenethyl) - phenylazo7-5-pyrazolone, l-phenyl-3-Nn-hexylcarboxamido-4-p- 2 ', 5' -dihydroxyphene thyl) -phenylazo7-5-pyrazolone (compound III), 1- phenyl -3-carbethoxy -U - / p- (2 ', $' -dihydroxyphene thyl) -phenylazo7-5- pyrazolone, 2-Lp- (2 ', 5'-dihydroxyphenethyl) -phenylazç7 - / - iço- propoxy -1-Naphthol, 1-peryl-3-N-cyclohexylcarboxamido-4-p- (e ', 5'- dihydroxyphenethyl) -phenylaz-07-5-pyrazolone, 1-phenyl-3-phenyl- 4 p- (2 ', 5'-dihydrophenethyl) -phenylaz-5-pYrazolone, 2- (4'- p-2 ", 5" -dihydroxyphenethyl) -phenylazQ7-alpha-naphthylazo) -4-methoxyl-1-naphthol, the 1-Phenyl-3-dmino-4- (4 'p- (2 "5" -dihydroryphenethyl) - phenyiaz-2,5'-diethozyphenylazo) 5-pYrazolone, 1-acetoxy-2- / p- (beta hydroquinonylethyl) -pheny2.zo7-AHnethoxynaphthalene, 4- isobutoxy-2-p- (beta-hydroquinorylethyl) -phenylaz-1-naphthol,

   1-acetozy-2 - (beta-hydroquinonylethyl) -phéxplaz-l-proy- naphthalene, Z-rp- (2 ', 5'-di2ydroay -!' - methylphenethyl) -phenyhaz- 4-propoxy-1-naphthol , 1-Phenyl-3- / N- (beta-ethylhexyl) -carboxamldo7-, 4-5- (beta '-hydroquinonylethyl) -phenylazo 7 -5-pyrazolone, 1-phenyl-

 <Desc / Clms Page number 23>

 
 EMI23.1
 3- (Nn-heptyl) -carboxamido-4-Z --p- (beta-hydroquinonylethyl) -phenyl- azo7-5-pyrazolone, 1- (o-carboxyphenyi) -3-phenyl-4- / p lactone - (2, 5-trifluoroacetoxy-beta-phenylethyl) -phenylazo7-5-hydroxy-pyrazole or 1- (o-carboxyphenyl) -3-N-phenylcarboxamido-4-p-beta'- hydroquinonylethyl) -phenylaz-5- hydroxypyrazole.



   Another class of developing dyes, described in the aforementioned French patent 1,168,292 corresponds to the formula
 EMI23.2
 general QY (gm) -A- (N - Z - D) m or Y (8-m) - A - (N - D) m where A represents an anthraquinone nucleus, D an organic radical with developing function and containing a nucleus aryl, such as benzen or naphthalene, bearing at least two substituents selected from hydroxyl, amino and amino groups substituted such that the compound can develop the exposed silver halides, Q a hydrogen atom or an alkyl group or, when the substituents on the aryl ring of D are hydroxyl groups, an aliphatic (eg acetyl) or aromatic (eg d ple, benzoyl) acyl group, Z is a divalent organic radical containing at least one group methylene (CH2),

   m a positive integer less than 5 and each Y a halogen or hydrogen atom or an a.nino, alkyl, aryl, nitro, alkylamino, arylamino, aryloxy, alkoxy, hydroxyl, sulfonamido, carboxamido, carboxy, sulfo group , Q - N - D or Q - N - Z - D.

   Examples of such developer dyes
 EMI23.3
 are 1,4-bis- (2 ', 5'-dihydroxyanilino) -anthraauinone, 1,5-bis- (', 5'-dihydroxyanilino) -h, ô-dihydroxy-anthraçuinone, 1,4-bis - Lbeta- (3 ', 4'-dihydroxyphenyl) -éthyZamin-anthraquinone, 1,4-bis- Lb2ta- (2', 5'-dihydroxyphenyl) -isopropylamin-anthraquinone (blue-green developing dye) of formula :

 <Desc / Clms Page number 24>

 
 EMI24.1
 
 EMI24.2
 l, l-bis ta- (2,5'-dibydrorghényl) -étb, ylaminQ7-anthraquinone, 1-chloro-4 ts :-( 2 ', 5'-dihydrox3rphyl) -étbylaminq-anthraquinone, lnonobenzoyl-1 , 4-bis eta- (3 ', 4'-ditydroYPhénYl) -eth, Yl.mino-T- anthraquinone, N-monobenzoyl-1,4 - bis- / betaA- (2', 5'-dihydroxyphenyl) -tylam3n -rn: raquinone, la -5,8-dinydroxy-1,4-bis / "" (beta-hydroquinonyl-alpha-metbyl) ethylamln27-anthraquinone (compound I);

   1,4-bis-L (beta-hYdroquinonyl-alpha-ethyl) -ethyl-anthraquinone, 5-hydroxy-1,4-bis- ± - (beta-hydroquinonyl-alpha-methyl) - ethylaaino7-anthraquinone , 1- (beta-hydroxy-alpha-ethyl-ethylamino) -4 - (beta-hydroquinonyl-alpha-methylethylamlno) -anthraquinone and 1- (butanol-2'-amino) -5,8-dihydroXY-4 -hydroquinonyl-isopropylamin0- anthraquinone.



   In the foregoing formulas, the term “bivalent organic radical” is understood to mean an organic radical whose two free valences are not satisfied by the same atom. As examples of such radicals, mention may be made of alkylene radicals such as
 EMI24.3
 -CH2r, -132-CH-, -CH2-CH-CH3, as well as divalent radicals such as -CH2-Ph- (end being a benzene ring). In addition, it is understood that Z can be its cure, unsaturated as -CH2-CH = CH-CH2- or subustituated, as in the chloroalkylene or hydroxyalkylene radicals.

   When Z is an alkylene group, the best results are obtained with a lower alkylene group, that is to say containing less than six carbon atoms, and especially with an ethylene group (-CH2 - CH2-). However, alkylene groups containing a larger number of carbon atoms can be used, provided

 <Desc / Clms Page number 25>

 The corresponding developing dye can dissolve in the liquid treatment composition described herein and its oxidation product is not diffusible into the developed emulsion layer.



   The acylation of the amino nitrogen atoms that are part of the chromophore has the effect of shifting the absorption band of the compound in the visible towards the larger frequencies (shorter wavelengths). This is how the acylation of a nitrogen atom
 EMI25.1
 amino of 1,4-bis-eta- (2 ', 5'-dihydroxdiphenyl) -ét.hylanin, ¯ anthraquinone (blue-green) changes this compound to magenta and acylation of the two amino nitrogen atoms changes to orange-yellow. Likewise, it can be expected that the acylation of the hydroxyl groups of the above-mentioned classes of developing dyes will alter the color of the developing dyes.

   The developing dyes may therefore undergo a structural and / or color change during development, for example by hydrolysis, so that the carried over dye may be of a different color from that of the developing dye initially present in the photographic material. than.



   T'other developing dyes are described in Belgian patents 554,935 filed February 12, 1957, British - 804,971, 804,973, 304,974 and 804,975 all four filed March 9, 1955 and the French patent 1,168,292 cited above.



   The following developing dyes are also useful for the implementation of photographic products and the process according to the invention: - cyanide developing dyes, such as
 EMI25.2
 2-hydroquinone-amino-4- (p-phenylazo) -anilino-6-hydro-4- triazine (Canadian patent 579,038, applied for March 28, 1958), - anthraquinone developing dyes, such as
 EMI25.3
 1,4-bis- (2 ', 5'-di.hydroaanilino) -anthraquinone and 1,4-diamino- N- (beta-2 *, 5' -dihydroxyphenyl-alpha-methylethyl) -2,3- anthraquinone- dicarboximide,

 <Desc / Clms Page number 26>

 - amino-substituted anthraquino-developing dyes, as prepared by reaction of the sodium salt of
 EMI26.1
 1-amlno-- (p-aainoanilino) -anthraquinone-2-sulfonic acid on chloroacétaaido-hydroquinone monobenzoate,

   - developing dyes obtained by reacting l-phenyl-3-aaino-4-phenylazo-5-pyr.azolone or 1,4-bis- (beta-aminoethylamino) -anthraquinone with lactone or chloride of acid of homogentisic acid or on the acid chloride of gentisic acid, for example 1-phenyl-3- (2 ', 5'-dihydroyphen, ylacetamido) -4.-phenyla2o-5-pyrazolone (Canadian patent 577,021 applied for October 17, 1955), - naphthamide developing dyes, such as
 EMI26.2
 1 - (2, 5 -dimé thoxyphény lazo) -2 -hydroxy -N - (2 ', 5' -dihy droxyphenyl) -3 - naphthamide (French patent 1,168,292 cited above), - dyes developing diazolques, such as
 EMI26.3
 z-Lp- (1-hydroxf-3, -di sul fo-8-ino-2-napht;

  2azo) -3, 3 '-dimé thoY- Disphenylazo7-hydroquinone and 2- (21,51-dimethocj-41-, 5- (2 ", j" -di hyc3ro.; Phene thyl) phenylaz> -phérlazo ) -1, 8-dihydrouap "talene-3,6-disulfonic acid, - arylazonaphtholic developing dyes, such as
 EMI26.4
 as l-anino -.- phenylazo-2-naphthoi, - anthrapyridonic developing dyes, such as 1-acetyl-3-bta- (2 ', 5'-dihydroayphen;

  rl) -ethyl-6-beta- (2 ', 5'- dihydro-Vp'bényl) -ethylaminoanthrapyridone, - thiohydroquinol developing dyes, such as 1-phenyl-3-methyl-4-, p- (2' , 5'-dihydroaryphenylthioethyl) - phen, ylaz> -5-pyrazolone (Belgian patent 568,344 applied for on June 5, 1958), - ortho-coupled developing dyes exhibiting limited sensitivity to pH variants, such as 2- ( p-
 EMI26.5
 L 2tt, 5tt-dihydroYdipheny-phenyLazo) -4-methoxy-1-naphthol and 1-phenyl-3-siethyl-4! P- (hydroquinolylsulfonyl} -phêlaz> 5-pyrazolone, - oxalyl ester developing dyes, such as 1-phenyl-3 mino-lp- (2 ', 5'-bis-ethyloxalyloz', yphenethyl) -

 <Desc / Clms Page number 27>

 
 EMI27.1
 phenylazo7-5-pyrazolone.



  It is also possible to use leuco-compounds, such as 1-phenyl-3-aethYl - (2'-me3'1-4'-diethylamino) -anilino-5-pyrazolone, which have no The filtering action on the underlying emulsion layers, which are immobilized in the developed regions, which diffuse towards the receptor product in the undeveloped areas and which oxidize there, forming color images.



   A variety of methods can be used to incorporate the developer dyes into the emulsion layers or adjacent layers. For example, they can be dissolved in organic solvents and precipitated in gelatin solution or they can be bead milled in gelatin solutions to reduce their particle size.

   However, particularly favorable results are obtained when hydroquinone compounds of the above types are, according to the invention, present in one or more of the layers of the photographic material and the developing dyes have been incorporated into the gelatin layers. located under the emulsion layers (Fig.l) by dissolving in high boiling point solvents, such as adipate
 EMI27.2
 iitetrahydrofurfuryl or 2- (2-butoxyethoxy) -ethyl acetate and passage through a colloid mill of the mixture of this solution with,; - gelatin solution.

   When using high boiling point solvents with low solvent action on developing dyes, for example dibutyl phthalate, the developing dye should be dissolved in a mixture of such a solvent and a low point solvent. such as cyclohexanone, methanol, etc., which spontaneously evaporates during subsequent drying of the layers.

   Many developer dyes dissolve (in the absence of low boiling point solvents) in high boiling point solvents, such as ditetrahydrofurfuryl or beta-methoxyethyl phthalates, N, N-
 EMI27.3
 ethyl di-n-butylcarbamate, o-methoxyphenyl acetate, tetrahydrofurfuryl propionate, triethyl or acetyl citrate

 <Desc / Clms Page number 28>

 triethyl, tricresyl, tri-p-tertio-butyl-phenyl, triethyl, tri-n-butyl or triphenyl phosphates, isoamyl or methyl acetate, ditetrahydrofurfuryl succinate or adipate, tetrahydrofurfuryl benzoate, Nn- amylphthalimide, ethyl NN-di-n-butylcarbamate, diethyl- or dibutyllauramide,

   lauroyl-piperidine, N-n-butylacetanilide, tetraethyl-phthalamide, N-n-amyl-succinimide, 4-methyl-2-
 EMI28.1
 pentanol, 2, h-di-n-amylpheno7., ethylene glycol monobenzyl ether, methyl-isobutylcarbinol, furfuryl alcohol, cyclohexanone and 2- (2-buiozyethocy) -ethyl acetate .



  The 2-, 3- and 4-methylyclohexanones isomers are particularly useful low boiling point solvents for dispersing, together with the above high boiling point solvents, developing dyes such as 1,4-. bis- (2.5-
 EMI28.2
 hydroxyphenylisopropylamino) -anthraquinone, 5,8-bis-rbeta-hydroquinoyl-alpha-aiethyl) -ethylamino7-quinizarin and 1,4-bis- (25'-dihydroxyphenylisopropylamino) -5-hydro-xyanthraquinone and developing dye magenta 4 -methoxy-2-5- (beta-hydroquinoyl-ethyl) -phenylazo7-1-naphthol. Gelatin solutions containing these developer dye dispersions give stable layers after drying in which these compounds do not tend to crystallize out.



   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, as shown in FIG. 1. It is less advantageous to place the developer dye in a layer above the corresponding emulsion layer.

   The contiguity condition of the developing dye and the halides

 <Desc / Clms Page number 29>

 silver can be satisfied by a "packet" system in which the developer dye is incorporated into a matrix embedding a particle or globule containing silver halide grains.



   In multi-layered photographic elements of the type shown in FIG. 1, the order of superposition of the various layers of differently chromatized silver halide emulsions on the support may be different, i.e. reversed so that the blue sensitive layer is closest of the support and the farthest red-sensitive layer. In such layering arrangements, the sensitivities of the emulsions must be adjusted so as to prevent registration of the blue image component in emulsions primarily intended to register red and green; for this, a 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 unwanted filtering action on the blue-sensitive emulsion layer 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 dibasic acid esters, 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 using gelatin intermediate layers,

 <Desc / Clms Page number 30>

 as shown in Fig. 1, their thickness must be at least equal to about three-quarters of the thickness of the layer of yellow developing dye and they must contain an amount of gela- tin at least about double the amount of gelatin in that same layer, so preventing the diffusion of the developing dye and the developing products from layer to layer.



  Other hydrophilic organic colloids give poorer results in the layers. For example, when some of the layers contain gelatin as a binder and polyvinyl alcohol or cellulose acetomophthalate intermediate layers are used, the layers tend to separate, particularly when dry. In addition, when gelatin is used for all layers, a more even distribution of the basic processing liquid and hydroquinone compound is achieved in the layers and the developing dyes forming the proof carry over to the product more easily. receiver.



   The processing liquid used to initiate 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 as much as possible. developer dye. 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 tests with a tendency to. decompose the image of coloring.

   As already indicated, since the 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 one obtains. satisfactory results in other respects. We get the best

 <Desc / Clms Page number 31>

 their results when the hydroquinone compound is present in the layers of the photographic element, 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 receiver material, they can be released by a suitable agent, such as pressure or heat.



   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 through the use of frangible capsules to contain this liquid, as shown in FIG. 1 or by means of other devices making it possible to spread this liquid uniformly over the exposed image or over a series of consecutive exposed images, in contact with the receiving product. Therefore, it may be desirable to use a processing liquid which contains, in addition to the strongly basic compound, a thickening agent, such as high viscosity carboxymethylcellulose or hydroxyethylcellulose, in an amount sufficient to provide the desired viscosity.

   Other means can be used, such as fine dispersion spraying, immersion, roll transfer, etc. 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 receiving material to obtain several color proofs in a single transfer operation. .



   A process for obtaining color proofs from a strip of photographic material containing a

 <Desc / Clms Page number 32>

 series of consecutive views, for example three or four, consists in applying a viscous treatment liquid contained in a frangible or opening envelope, inside a compartment, such as a store, secured to the device for taking views, as indicated below, so as to moisten each of the views with the treatment liquid, almost simultaneously, in contact with a strip of the receiving product and to transfer the corresponding polychrome images onto the latter to form on a single product sheet receiving a series of color proofs.



   Another method of obtaining prints from the photographic product bearing a series of consecutive views, for example three or four, consists in exposing this product in a camera of the conventional type, 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, thanks to the winding on a coil of typ- su-l avecc protective backing paper or in a cartridge or binder.



  The exposed photographic product is then introduced into a portable, light-tight box of small dimensions, as shown in FIG. 3, so that it receives the treatment liquid contained therein, for example in a single frangible container or in a number of frangible containers equal to the number of views exposed, or applied by a wick, roller or equivalent device, so that every exposed view is moistened.

   As a result, the photographic element 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 found moistened with the. basic liquid in the presence of cationic onium salts and in the presence also 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 areas exposed of each layer

 <Desc / Clms Page number 33>

 emulsion are developed, and thus the corresponding developing 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. Fig. 3 is a diagrammatic representation of an apparatus which can be used for this embodiment of the invention. The film 40 wound up with the emulsion inward, and having the structure shown in FIG. 1 (upper section), is drawn rapidly between rollers 41 and 42 to be wetted with the basic treatment liquid 43 (for example, activator II of the formula given below) contained in the cuvette 44.

   The film then passes between rollers 45 and 46 which apply it in contact with an etched receiver sheet 47 (eg, receiver sheet described below) to form the complex product 48 which then leaves the apparatus. When the two products are separated, a series of positive images consisting of developing dyes is obtained on sheet 47, at 50.



   The cameras allowing, in addition to 1 exposure, the development and the transfer of an image on a receiving product inside the apparatus itself are well known and have been described, for example, in the patent. of the United States of America No. 2,435,717, requested October 6, 1945. Such apparatuses can be used for practicing the invention.



   Receiving products which can be used according to the invention comprise a suitable support, such as a sheet of paper, transparent film or cellulose ester film with white pigmentation, on which an image-receiving layer is applied.



  The latter can be constituted by various substances, such as linear polyamides, proteins (for example gelatin), polyvinylpyrrolidones, poly-4-vinylpyridines, polyvinyl acetate, polyvinyl alcohol, cellulose acetate, salicylalpolyvinyl, partially hydrolyzed polyvinyl acetate, methylcellulose, regenerated cellulose, carboxymethyl-

 <Desc / Clms Page number 34>

 cellulose and hydroxyethylcellulose.



   Like other processes where images are formed from dyes, these are somewhat sensitive to the action of heat, light and humidity. It is therefore advantageous to process the tests to remove them as much as possible from this action. For this, solutions of certain compounds which improve the stability of the dye images, for example solutions of tannic acid, a condensation product of naphthalenesulfonic acid and formaldehyde, and polyvinylpyrrolidone, can be applied to the tests. A particularly useful synergistic composition is a solution of polyvinyl alcohol containing a saccharide, such as mannite, levulose, arabinose, maltose, amnose, etc .; neither polyvinyl alcohol alone nor saccharide alone effectively protects images from developing dyes.



   It may be desirable to incorporate a growth inhibitor into the photographic material, basic processing liquid or recipient material or each of these, as well as a development arrest compound to the recipient material. When development arrest compounds are present in the receiving material, and not in the photographic element or in the processing liquid, they cannot work until they have been dissolved by the processing liquid and have reached the photographic product under development. As a result, the latent image can develop very quickly and the development is not significantly inhibited until the exposed patches are almost 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 receiving layer and the indicated quaternary salts are present in the treatment liquid or in the receiving layer or both. Suitable development inhibitors are heterocyclic mercaptans, such as mercaptotetrazoles and mercaptobenzothiazoles, e.g.

 <Desc / Clms Page number 35>

   1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, etc.



  Many of the compounds which are commonly considered to be haze inhibitors for silver halides do not sufficiently inhibit growth 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 thiosulfate 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 mentioned hydrequinone compounds 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 ranges of the photographic element and its carry over. on the receiving layer.



   The invention extends to photographic elements whose support is adapted to receive the images of developing dyes 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 peeling. 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 following non-limiting examples illustrate the invention.



    EXAMPLE 1. Derivatives of hdyroquinone in the outer layer.



   A sensitive product is prepared having the structure shown in FIG. 1 (upper diagram) by applying on a substrate film substrate 10 the following gelatin layers, suitably tanned.

 <Desc / Clms Page number 36>

 



   Layer 11.



   Aqueous gelatin solution containing a blue-green developing dye (compound I) in a mixture of N-n-butylacetanilide, 4-methylcyclohexanone and the dispersing agent Alkanol B.



  The mixture is passed through a colloid mill several times, then this solution is coated and dried to volatilize the 4-methylcyclohexanone.



   Layers 14, 15 and 16.



   Gelatin silver bromoiodide emulsion layers sensitized to red, green and blue, respectively.



   Layers 17 and 18.



   Gelatin interlayer.



   Layer 12.



   This layer is obtained from an aqueous gelatin solution containing the magenta developing dye (compound II) dissolved in a mixture of cyclohexanone, Nn-butylacetanilide and Alkanol B. This solution is passed through a colloid mill several times. the layer and dried to volatilize the cyclohexanone.



   Layer 13.



   This layer is obtained from an aqueous gelatin solution containing the yellow developing dye (compound III) dissolved in a mixture of di-tetrahydrofurfuryl adipate, ethylene glycol monobenzyl ether and Alkanol B. mixing several times in a colloid mill the dispersion is cooled to gel, washed to remove ethylene glycol monobenzyl ether, applied to layer 18 and dried.



   Layer 19.



   D-1 dispersion of the hydroquinone derivative.



   Part A.
 EMI36.1
 



  4'-methylphenylhydroquinone ............... 136 g Methyl alcohol ......................... 136 ml Di-n-Butyl phthalate .................. 272 ml

 <Desc / Clms Page number 37>

 
We heat this email. ge at 70 C to dissolve it, then it is cooled to 40 C.



   Part B.



   10% gelatin solution 1360 ml
Water ................................... 1360 ml
5% aqueous solution of Alkanol B ..... 136 ml This mixture is heated to 40 ° C.



   Part A is slowly heated to part B with mechanical stirring. The resulting solution is then passed five times through a Manton-Gaulin laboratory colloid mill. The colloid mill is then rinsed, the dispersion is adjusted to a weight of 3775 g, it is gelled and it is stored in a refrigerator.



   The coating composition is prepared to form the layer 19 by operating as follows:
Part I.



   Dispersion D-l 3775 g
Water 2225 ml
This mixture is heated to 40 C.



   Part II.



   10% gelatin solution .............. 3180 g
Water ..................................... 12,000 ml
Mucochloric acid (aqueous solution
2.7%) 515 ml The mixture is heated to 40 ° C. and the pH is adjusted to 5.5.



   Parts I and II are combined and diluted with water to 22,700 ml. This solution is applied to form the layer 19 of FIG. 1 at a rate of approximately 1280 mg of gelatin per square meter and 428 mg of 4-1-methylphenylhydroquinone per square meter, hereinafter referred to as HQ.



   Samples of the product obtained (n 71) exhibiting the structure shown in Fig. 1 (upper diagram) and samples of an identical product (n 68) are then exposed to the same original.
 EMI37.1
 but which does not contain 4'-methylphenylhydroquinone in layer 19, and they are wetted by activators I, IIQ and IIIQ

 <Desc / Clms Page number 38>

 (as indicated below) by bringing them into contact with a receiver sheet A (as indicated also below), which consists of the support 20 and the receiver layer 21 (tests 1 to 6).

   As a result, the silver halides in the exposed areas 23, 24 and 25 of each sample are developed, the developing dyes in the adjacent areas of the underlying layers 11, 12 and 13 are immobilized depending on the development, and the dyes which unreacted diffuse following images and registering on the receiver sheet to give a colored positive image consisting of images 26, 27 and 28 as shown in the lower diagram of FIG. 1.

   In this process, due to the presence of picolinium salts and in part of that of 4-methylphenylhydroquinone in the film, the developing dyes of layers 11, 12 and 13 are immobilized in the appropriate amount and in the appropriate layers in such a way. that the color proofs obtained show larger, brighter lights (lower minimum density), that the color selection is improved and the loss of saturation is reduced compared to the control film No. 68 containing no HQ.



   The results of tests 1 to 6 shown in the following table show the improvement in the minimum density in the neutral scale of the tests as a result of the use of quaternary salts. These tests show that when the product not containing HQ is treated with activators IIQ and IIIQ (tests 2 and 3) the minimum densities in the neutral scale of tests 2 and 3 obtained in red light and in green light are reduced compared to test 1 where the activator does not contain quaternary salt - In addition, visual examination of samples from tests 2 and 3 shows that the color contamination is reduced and that the loss of saturation is considerably reduced - From tests 4 to 6 it can be seen that, while the HQ by itself decreases the minimum density (test 4),

   on the other hand, when the quaternary salt is present (tests 5 and 6), an additional reduction in the minimum density is obtained.

 <Desc / Clms Page number 39>

 



  EXAMPLE 2. Hydroquinone Derivatives in the Emulsion Layer.



   A film # 69 of identical structure to that of Example 1 was prepared except that a sufficient amount of dispersion D1 was added to emulsion layer 16 (rather than layer 19) to obtain 480 mg of 4'-Methylphenylhydroquinone (HQ) per square meter. This product is treated as in Example 1, using activators I, IIQ and IIIQ with the results shown in the following table (tests 7,8 and 9), where it can be seen that results similar to those of Example 1. Further improvements are obtained with regard to color contamination and loss of saturation.

   It should be noted that the combination of the hydroquinone derivatives in the product and the quaternary salt used in the process (tests 1 to 9) gives improvements in color quality considerably greater than what is obtained when one of these compounds is used in isolation.



    EXAMPLE 3 Solvent for Silver Halides and Dyridinium Salt in the Activator.



   Films were prepared as in Example 1, except that film no.15 did not contain HP, film no.18 contained 430 mg of HQ per square meter in layer 19, film no.14 contained 430 mg of HQ per square meter. square meter in layer 18 and that film 75 contains 430 mg of HQ per square meter in layer 17. The films are treated with IVQ and V activators shown below each containing sodium thiosulfate as sol--.int arent halides, the IVQ activator also containing the pyridinium salt.

   As indicated by the results of tests 10 to 17 reported in the following table, improved colors, reduced minimum densities, and also reduced contamination and loss of saturation are obtained, regardless of the position of the HQ in the film, and, in particularly when the pyridinium salt is present in the activator solutions.



    EXAMPLE 4. Pyridinium salt in the receiver sheet.



   The film No. 68 prepared as in Example 1 is exposed

 <Desc / Clms Page number 40>

   (without HQ in layer 19), yarn * n * 69 of example 2 (HQ in layer 16) and yarn n 71 (HQ in layer 19), they are wetted by activator I on contact of the receptor product B indicated below and containing the pyridinium salt, to transfer polychrome images to the receptor product.

   As a result, the color qualities of the obtained proofs are much improved over those of similar proofs prepared on the receptor A product which does not contain pyridinium salt. The density values from runs 18, 19 and 20 show that the HQ in layers 16 and 19 and the pyridinium salt in receptor B cause a significant reduction in minimum densities as well as an improvement in contamination and fading colors.



   Activator I.



   Aqueous solution containing 3.5% high viscosity hydroxyethylcellulose, 4.5% sodium hydroxide and 2% benzotriazole.



   Activator 110.



   Activator I plus 2.0% 1-phenethyl-2-picolinium bromide.



   Activator IIIQ.- Activator I plus 2.0% 1-benzyl-2-picolinium bromide.



   IVO activator.



   Activator IIIQ plus 1.0% sodium thiosulfate.



     Activator V.



   Activator I plus 1% sodium thiosulfate.



   Activator VI ,.



   Aqueous solution containing 4% of carboxymethylcellulose,
4% sodium hydroxide, 1% sodium thiosulfate, 0.2% 5-nitrobenzimidazole, 5% hexamethylenetetramine.



   Activator VII.-
Activator VI plus 2% 1-phenethyl-3-picolinium bromide.

 <Desc / Clms Page number 41>

   Activities VIII.-
Activator VI plus 2% 1-phenethylpridinum bromide.



  Activator IX.-
 EMI41.1
 Aqueous solution of 2.5 carboxymethyleuulose, 3.5% sodium hydroxide, 0.2 6-nitrobenzimidazole, 1% sodium thiosulfate, 0.4; 2,5-bis-ethyleneiminohydroquinone, 0.6% 1-phenyl-3-pyrazolidone and 10% ethylene glycol.



  Activator X.-
Activator IX plus 0.4% cetyltrimethylammonium bromide.



  Activator XI.



   Activator IX plus 0.6% para-toluenesulfonate
 EMI41.2
 tetradecyldime hylsulfoniuca.



  Receiver sheet A.



   White pigmented cellulosic ester support carrying a gelatin layer containing a mixture of poly-4-vinylpyrindine as mordant and 1-phenyl-5-aercaptotetrazole.



  Receiver sheet B.



   White pigmented cellulose ester support, carrying a gelatin layer containing a mixture of poly-4-vinylpyridine, 1-phenyl-5-mercaptotetrazole and 1-phenethyl-2-picolinium bromide.



   Similarly, the other effective hydroquinones can be used in films containing the developing dyes and other effective quaternary salts, preferably in the alkaline treating solution and / or in the receiving layer.



  EXAMPLE 5. -
In the same way as in Example 1, but using the IVQ activator, 53 mg, 107 mg, 214 mg, 430 mg and 1070 mg of HQ are incorporated respectively per square meter in layer 19. It is possible to observe while the improvements are obtained from 53 mg and 107 mg. However, optimal results are obtained in the interval

 <Desc / Clms Page number 42>

 from 214 mg to 1070 mg.



   Similar results are obtained when the same series of concentrations is used in layer 16.



  EXAMPLE 6.-
In the same way as in Example 1, but using the IVQ activator, the following hydroquinones are used in layer 19.
 EMI42.1
 



  CpAposé MgIul2 Compound n me / m 2 4e-Chlorophenylhydroquinone 470
3 Phenylhydroquinone 300
4 Phenoxyhydroquinone 430
5 2,5-dioctylhydroquinone 535
The improvements obtained are analogous to those of the previous examples where HQ is used. However, it was noted that compounds 2 and 3 give somewhat better results.



    EXAMPLE 7. -
In the same way as in Example 1, the film is treated with activators VI, VII and VIII with the result that the films treated with activators VII and VIII containing the quaternary compounds have minimum densities lower than the film treated with activator VI without quaternary salt.



    EXAMPLE 8.-
The films containing the developing dyes of Example 1 are treated with activators IX, X and XI. The films treated with activators X and XI containing the quaternary ammonium and sulfonium salts, respectively, exhibit lower minimum densities of yellow, magenta and blue-green than the same films treated with. activator IX in the absence of quaternary salt or sulfonium salt.



  EXAMPLE 9. -
In the same way as in Example 1, the dispersion D1 of layer 19 is replaced by a dispersion in which cyclohexanone is used in place of methyl alcohol and, in place of di- phthalate. n-butyl, a proportion ten times

 <Desc / Clms Page number 43>

 less diethyllauramide. As a result it was found that the layer 19 can be coated to a much smaller thickness, that the sensitive product exhibits a much greater developer permeability and that the prints obtained show a lower contamination of the colors.



   BOARD.
 EMI43.1
 
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<tb> example <SEP> test <SEP> vateur <SEP> receiving <SEP> scale <SEP> of neutral <SEP>
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<tb> ¯¯¯¯¯ <SEP> ¯¯¯¯¯ <SEP> ¯¯¯¯¯¯¯¯¯ <SEP> trice <SEP> Red <SEP> Green <SEP> Blue
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<tb> 1 <SEP> 1 <SEP> 68 <SEP> (indicator) <SEP> I <SEP> A <SEP> 0.69 <SEP> 1.15 <SEP> 1.72
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<tb> 1 <SEP> 2 <SEP> "<SEP>" <SEP> IIQ <SEP> A <SEP> 0.45 <SEP> 0.55 <SEP> 1.76
<tb>
<tb>
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<tb> 1 <SEP> 3 <SEP> "<SEP> IIIQ <SEP> A <SEP> 0.53 <SEP> 0.68 <SEP> 2.00
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<tb> 1 <SEP> 4 <SEP> 71 <SEP> (HQ <SEP> in <SEP> 19) <SEP> I <SEP> A <SEP> 0.55 <SEP> 0.69 <SEP> 0 ,

  95
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<tb> 1 <SEP> 5 <SEP> "<SEP> IIQ <SEP> A <SEP> 0.32 <SEP> 0.25 <SEP> 0.26
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<tb> 1 <SEP> 6 <SEP> "<SEP> IIIQ <SEP> A <SEP> 0.31 <SEP> 0.23 <SEP> 0.41
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<tb> 2 <SEP> 7 <SEP> 69 <SEP> (HQ <SEP> in <SEP> 16) <SEP> I <SEP> A <SEP> 0.48 <SEP> 0.58 <SEP> 0 , 69
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<tb>
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<tb> 2 <SEP> 8 <SEP> "<SEP>" <SEP> IIQP <SEP> A <SEP> 0.25 <SEP> 0.27 <SEP> 0.32
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<tb> 2 <SEP> 9 <SEP> "<SEP> IIIQ <SEP> A <SEP> 0.29 <SEP> 0.29 <SEP> 0.37
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<tb> 3 <SEP> 10 <SEP> 15 <SEP> (indicator) <SEP> IVQ <SEP> A <SEP> 0.70 <SEP> 0.57 <SEP> 0.96
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<tb>
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<tb> 3 <SEP> 11 <SEP> "<SEP>" <SEP> V <SEP> A <SEP> 0.72 <SEP> 1.20 <SEP> 1.46
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<tb> 3 <SEP> 12 <SEP> 18 <SEP> (HQ <SEP> in <SEP> 19) <SEP> V <SEP> A <SEP> 0.27 <SEP> 0,

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<tb> 3 <SEP> 13 <SEP> "<SEP>" <SEP> IVQ <SEP> A <SEP> 0.27 <SEP> 0.21 <SEP> 0.25
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<tb> 3 <SEP> 14 <SEP> 14 <SEP> (HQ <SEP> in <SEP> 18) <SEP> V <SEP> A <SEP> 0.21 <SEP> 0.44 <SEP> 0 , 90
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<tb> 3 <SEP> 15 <SEP> "<SEP>" <SEP> IVQ <SEP> A <SEP> 0.25 <SEP> 0.20 <SEP> 0.25
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<tb> 3 <SEP> 16 <SEP> 75 <SEP> (HQ <SEP> in <SEP> 17) <SEP> V <SEP> A <SEP> 0.23 <SEP> 0.76 <SEP> 1 , 29
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<tb> 3 <SEP> 17 <SEP> "<SEP>" <SEP> IVQ <SEP> A <SEP> 0.23 <SEP> 0.20 <SEP> 0.26
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<tb> 4 <SEP> 13 <SEP> 68 <SEP> (indicator) <SEP> I <SEP> B <SEP> 0.53 <SEP> 0.89 <SEP> 2.32
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<tb> 4 <SEP> 19 <SEP> 69 <SEP> (HQ <SEP> in <SEP> 16) <SEP> I <SEP> "<SEP> 0.31 <SEP> 0,

  41 <SEP> 0.89
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<tb> 4 <SEP> 20 <SEP> 71 <SEP> (HQ <SEP> in <SEP> 19) <SEP> I <SEP> "<SEP> 0.20 <SEP> 0.25 <SEP> 0 , 53
<tb>
 
In the silver halide emulsion layers and the adjacent layers of the sensitive products according to the invention can advantageously be used emulsion builders described, for example, at the first addition requested on May 5, 1959 and attached to the invention. French patent 1,224,012, applied for September 11, 1956, comprising salts of noble metals, stannous salts, polyamines, optical sensitizers, azaindenes and mercury salts as stabilizers, quaternary ammonium salts and poly- ethylene glycols as sensitivity enhancing compounds, plati

 <Desc / Clms Page number 44>

 strangers, tanners,

   coating aids and colloidal binders.



   Of course, the invention is not limited to the embodiments described and shown which have been chosen only as examples.


    

Claims (1)

ABSTRACT. The objects of the invention are in particular 1 - a color reversal-transfer process, a process 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 emulsion to the silver halides of different chromatic sensitivities, a developing dye being placed adjacent to the silver halides of each emulsion layer, said developing dye being at the same time a silver halide developer and a dye, and a hydroquinone which is practically colorless and insoluble in water, but soluble and diffusible in alkaline solution, being present in a layer on said support, an alkaline liquid is applied to the emulsion layers while they are in a position contiguous with a receiving layer and an onium compound, chosen from compounds of ternary sulfonium, quaternary phosphonium and quaternary ammonium, diffusible in solution alkaline, to develop the silver halides and make the developer dyes non-diffusible in the areas where exposure and development take place, the developer dyes of the unexposed areas are allowed to diffuse following an image and in registration on the receiving layer, and separating the receiving layer to obtain a polychrome image on this receiving layer, which image is composed of the developing dyes; b) the hydroquinone indicated under 1 a) is chosen from the following compounds <Desc / Clms Page number 45> Phenylhydroquinone EMI45.1 2 '-hydroxyphenyihydroquinone Phenoxyhydroquinone 4'-methylphenylhydroquinone 1,4-dihydroxynaphthalene EMI45.2 2- (4-aminophenethyl) -5-bromohydroquinone 2- (4-aminophenethyl) -5-methylhydroquinone 4'-atainophenethylhydroquinone 2,5-dimethoxyhydroquinone 2,5-dibutoxyhydroquinone m-xylohydroquinone Bromohydroquinone 3,6-dethylichlorquinethyl-dimethoxyhydroquinone 3,6-dethylichlorquinethyl-dimethyl-ethyl-dimethoxyhydroquinone 3,6-dichloroquinone 3,6 -hydroquinone 3,6-hydichlorquinone 3,6 -hydroquinone cyclohexylhydroquinone Sec. butylhydroquinone 2,5-dichlorohydroquinone 2,5-diisopropylhydroquinone 2,5-diiodohyroquinone 3-chlorotolyhydroquinone Tetrachlorohydroquinone 2,5-diphenylhydroquinone EMI45.3 25-diresorcylhydroquinone 2, 5-diocty7.iydroquinone Dodecylhydroquinone c) hydroquinone is present in the layer furthest from the support; d) this hydroquinone is present in an emulsion layer; e) this hydroquinone is present in a non-photosensitive layer adjacent to at least one of the emulsion layers; f) the quaternary ammonium compound is a pyridinium salt which is present in the alkaline processing liquid; <Desc / Clms Page number 46> g) this pyridinium salt is present in the receptor layer; h) a photographic product is exposed which comprises a support carrying, in superposition and in the order of enumeration, layers of emulsion of silver halides sensitive respectively to red, green and blue, a a layer of a subtractive color developing dye adjacent to (and under) each emulsion layer, said developing dye being a compound which is both a silver halide developer and a dye, and a substantially colorless hydroquinone and insoluble in water, but soluble and diffusible in alkaline solutions, being present in a layer on the said support, the photographic product thus exposed is applied under pressure in contact with an etched receiving layer, a layer of an alkaline solution being placed between the emulsion layers and the receiving layer, and in contiguous position with a quaternary ammonium compound, diffusible in the solution, to develop the silver halides and render developing non-diffusible dyes in the exposure and developing regions, the developer dyes are allowed to diffuse in unexposed areas, image-tracking, and register on the receiving layer, and separating the receiving layer to obtain a full color image formed of said developing dyes on this receiving layer; i) a photographic product comprising a support having superimposed several layers of silver halide emulsion of different chromatic sensitivities of different color sensitivities, a subtractive color developing dye being in position 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, and a substantially colorless and water insoluble but soluble and diffusible hydroquinone in alkaline solution being present in a layer on the said support, the exposure <Desc / Clms Page number 47> being made in such a way that it gives latent images in different product areas, the product is applied under pressure on a receiving layer etched with a layer of an alkaline solution between the emulsion layers and the receiving layer and in contiguous position with a quaternary ammonium compound diffusible in the solution, to develop the silver halides and to render the developer dyes non-diffusible in the exposure and development ranges, the developer dyes in the unexposed ranges of the various exposure areas are allowed to transfer imagewise by diffusion and registration on the receiving layer, and separating the receiving layer to obtain full color images composed of the developing dyes in the various areas of the receiving layer; j) according to one embodiment ae 1 i), the quaternary ammonium compound is a pyridinium salt; 2 - as a new industrial product, a receiving product suitable for receiving images of developing dyes diffusing towards said product from layers of silver halide emulsion placed in contiguous position, said developing dye being a a compound which is at the same time a developer of the silver halides and a dye, the said receptor product being remarkable in particular by the following characteristics considered separately or in combinations a) it comprises a mordant for the said images of the dye developing agent and a substantially colorless hydroquinone and practically insoluble in water, but diffusible in alkaline solution; b) it further comprises an onium compound chosen from the compounds of ternary sulfonium, of quaternary phosphonium and of quaternary ammonium, diffusible in alkaline solutions.