DE2910271A1 - Polymer for timing layer of diffusion transfer material - subject to beta elimination in alkaline medium gives sharp change from impermeable to permeable state - Google Patents

Abstract

Polymer (I) used in timing layer of a photographic diffusion transfer unit, which is subject to beta-elimination in alkaline medium, has units of formula R"-CO-O-CAE-CHDY (in which R" is derived from a 2-5C ethylenically unsatd. alkyl gp. A, D and E are H, Me or Pb but are not all Me or Ph. Y is an activating gp.). The (I) layer passes rapidly from an impermeable to a permeable state after a certain time.

Description

Numerous diffusion transmission systems are known.

In general, an overlay image is obtained by having a light-sensitive element (negative component) with at least one light-sensitive element Exposing silver halide layer to form a developable image; this picture is then developed by applying an aqueous-alkaline developer liquid, and due to this development, an image-wise distribution of soluble and diffusible imaging material (which is a dye, a dye intermediate or a soluble silver complex) is generated. This pictorial distribution is then at least partially by diffusion onto an overlying image receiving element (positive component) containing an image receiving layer containing the Record transmission image.

The dye image-forming substances used in this process can generally be identified as substances that are used are initially soluble or diffusible in the developer composition and are then selective rendered nondiffusible as a function of development in a pictorial pattern will; but it can also be substances that were originally in the developer composition are insoluble or non-diffusible and which then function as a function of development can be made selectively diffusible in an imagewise pattern. In the patent literature are numerous examples of both types of color image-forming substances specified. A particularly useful class are developer dyes which also represent developer substances for silver halide), as they are, for example in U.S. Patent 2,983,606 and many other patents.

In all of these systems, multicolored images can thereby be obtained be that a photosensitive element (negative component) with at least two selectively sensitized silver halide layers are used, each Layer associated with a dye image forming material is, which shows the desired spectral absorption properties. The most common Elements of this type used are the so-called "tripack" structures those a blue-sensitive, a green-sensitive and a red-sensitive silver halide layer is used, each of which has a yellow, a purple and a cyan color image-forming agent Material is assigned.

In such a system, the negative and the positive components represent separate elements that are superimposed on each other during development and then held together or separated again to achieve the desired To deliver the transmission image (see e.g.

U.S. Patent 2,983,606); however, these two components can also be a unified one Form structure, e.g. the so-called integral negative-positive film units in which the respective components before exposure and after imaging stay together. In the latter system there is a reflective one Material, e.g. a white pigment such as titanium dioxide, between the two components.

This material can be a preformed layer or one during the Represent the layer formed by development, which masks the negative component and the desired background for viewing the in the positive component image generated as a reflection image. The corresponding component of this integral film units can be mounted on a single dimensionally stable support be present, or they can be located between two such substrates. Of course, each substrate should be assigned to which of the positive components must be transparent to allow viewing of the broadcast image.

Examples of such integral negative-positive film units for Generation of colored transfer images that are viewed without separation can be found in U.S. Patents 3,415,644; 3,415,645; 3,415,646; 3,473,925; 3,550,515; 3,573,042; 3,573,043; 3,573,044; 3,576,625; 3,578,540; 3,589,904; 3,594,164; 3,594,165; 3,607,285; 3,615,421; 3,615,436; 3,615,539; 3,615,540; 3,619,192; 3,619,193; 3,621,768; 3,647,437; 3,652,281; 3,652,282; 3,672,890; 3,679,409; 3,689,262; 3,690,879; and others.

In the case of multicolored diffusion transfer units such as those above in which two or more silver halide emulsion layers are used each layer containing its own dye image-forming material, can cause premature migration of the color-forming material during development lead to undesirable interimage effects, the dye or the other color-producing material at least partially due to the false silver halide layer is controlled, i.e.

by a silver halide layer to which it originally appeared in the Film unit did not belong.

This problem can also be seen from a common "Tripack" negative are explained with developer dyes, in which the negative is on a film base has the following layers: a red-sensitive silver halide layer, which has a blue-green Assigned to the developer dye, a green-sensitive silver halide layer, to which a purple developer dye is assigned, and a blue-sensitive one Silver halide layer to which a yellow developer dye is assigned. Ideally the solubilized developer dye should diffuse to its silver halide layer, and if he's not in that shift is bound, he should continue diffuse into the image receiving element. Diffusion through the silver halide layer is generally controlled by the development of the silver halide layer. If the developer dye can migrate to other silver halide layers before its silver halide layer is developed, the resulting transfer image has due to loss of dye and / or transfer of the wrong dye desired color fidelity.

To explain these difficulties further: If the purple one Diffuse developer dye back into the red-sensitive silver halide layer before this layer is developed by the cyan developer dye, some of the purple dye developer may have the silver halide in it Develop the "wrong" layer, where it is bound or made non-diffusible will. This leads to a loss of purple dye, i.e. a so-called "Purple waste" in the transfer image. It also enables the development of the red-sensitive Silver halide layer through the purple developer dye that part of the cyan developer dye which should be oxidized into the image-receiving element diffuses, resulting in undesirable cyan transfer.

In order to avoid or reduce these inter-image effects, already layers of different materials between the emulsions and their respective associated color image-forming substances inserted to a premature To prevent diffusion of the latter into a foreign silver halide emulsion. Such Interlayers are permeable to the developer composition, so that development the emulsions can take place on both sides of the intermediate layer. The intermediate layer is for the dye image forming material which is soluble by the developer composition was made briefly impermeable, so that the emulsions practically are fully developed before the dye associated with an emulsion layer can migrate through the intermediate layer to another emulsion layer.

Controlling the diffusion of color-producing substances by delay their diffusibility into the image-receiving layer until the desired degree of development is achieved is described in US Pat. No. 3,345,163. There the control is e.g. achieved by using a slowly hydrolyzable material as a barrier layer, the one outer emulsion layer and its associated color-producing substance of an inner emulsion layer and its associated color-generating substance separates.

Various other interlayer systems have also been used for photosensitive applications Elements described. For example, in US Pat. No. 3,615,422, two emulsion layers can be used by an intermediate layer of a metal-free polymeric material from each other be separated, which lets the developer through, but for the color-producing Substances is impermeable until the polymer is hydrated. The rate of hydration of the polymer is chosen so that the required hydration is only then achieved is when the silver halide emulsion has the lowest evaporation rate is practically fully developed and before in the emulsion layer with the significant fogging occurred at the highest fogging rate is. The intermediate layer can then both forward and back diffusion of color-producing substances or dyes. It delays the back diffusion that belonging to the silver halide emulsion layer closest to the outside Dye as well as the forward diffusion of the one closest to the inside Dye belonging to the silver halide emulsion layer.

Various polymeric substances found in such systems have proven particularly useful are described in US Pat. No. 3,421,892, which I refer to the use of interlayers made of polyvinyl amide.

These intermediate layers act like molecular sieves, their interstices can be enlarged by hydration of the polymer so that one molecule of one Dye or other color-producing substance can pass through.

The wipe sheet material described in U.S. Patent No. 5,384,483 is from an alkali-permeable, water-insoluble polyvalent metal salt of a film-forming, alkali-permeable and water-soluble polymers with free carboxylic acid groups composed. This polymeric salt, which fär the developer dye in aqueous alkaline Solution is less permeable than the polymer used to make it Carboxylic acid, apparently delays the diffusion of the developer dye into a foreign emulsion layer during development via a crosslinking mechanism, i.e. polyvalent metals form the required alkali-permeable, water-insoluble ones Salts by crosslinking with the carboxylic acid groups of the polymeric carboxylic acid. Will If these salts are hydrated during development, they swell so much that the non-oxidized Developing dyes diffuse into the image receiving element through their interstices can.

Instead of using an intermediate layer, that is essentially just that consists of a single material phase, intermediate layers of material mixtures can also be used use. Such a system is described in U.S. Patent 3,625,685, according to which Silver halide layers are separated by interlayers that are two intimate with one another mixed phases contain, namely a component that allows the penetration of the dye sets in motion and the discontinuous phase of one for the developer mass permeable material, and a coagulated latex phase (continuous Phase) from the coagulated base material of an aqueous, film-forming synthetic polymer dispersion. In this system, the material that forms the Penetration of the dye sets in motion and this is permeable for the developer mass or may be opaque and that may be opaque to the color image forming material is, a lattice structure with the coagulated latex, this the developer compound is permeable, after the contact with the developer mass it becomes the penetration the dye-initiating material, which is preferably a polyamide, for the läsllch made dye material permeable so that the dye through the Interlayer can go through.

In a preferred embodiment of that described above System becomes the intermediate layer by hydrating the discontinuous phase made permeable.

This phase expands in the hydrated state and creates spaces in the lattice structure of the intermediate layer, which are so large that the solubilized Dye can pass through. The rate of hydration and swelling is chosen in all,% 'eniein n so that the migration of the dyestuff-absorbing Material is blocked until the development of all emulsion layers in the photosensitive Element is practically finished; but one can also proceed in such a way that the development of the emulsions and the diffusion of the dye image forming material layer by layer he follows. In this system, an intermediate layer between two emulsion layers diminishes preferably such dye diffusion until the development of the external (closer the emulsion layer lying on the image receiving element is largely terminated.

As can be seen from the discussion above, polymers that permeable to the solubilized color image-forming material by hydration were made to be used alone or in admixture with other substances an intermediate barrier layer between two emulsions zs sit. It is believed that such an interlayer system ... Because of the size of the dye (or Dye precursor molecules can act as selective screens, although many @er Molecules of the developer compound, e.g. water, alkali sew. sine small enough to get through The gaps in the filter of the intermediate layer are the @@@ ekate of the solubilized dye-image-forming material too large to be removed during the for the photographic development estimated to penetrate it unless these spaces expand due to hydration of the barrier polymer.

Although these polymers act to retard the diffusion of dye image forming material have proven useful. was found, that they sometimes allow premature diffusion. This is because the Hydration of the polymer and the expansion of the intermediate layer in general as soon as the polymer comes into contact with the developer. It can so some dye diffusion will occur before development. the through the intermediate layer of the treasured silver halide emulsion largely completed is.

Furthermore, a relatively slow process occurs with these polymers Expansion of the intermediate layer. Instead of a very quick transition from one very impermeable state to a very permeable state as it is would often be desirable, the permeability of the intermediate layer usually only decreases reluctantly, i.e. it occurs too quickly and takes too long.

In U.S. Patent 3,362,819, image receiving elements are described which are particularly suitable for the aforementioned diffusion transfer processes and which contain a carrier layer, on one surface of which in the specified Order a polymeric acid layer, preferably an inert retardation or Spacer layer and an image receiving layer are attached after the transfer the diffusible dye image-forming suostan shows a visible image.

The acidic polymer layer should contain at least as many acid groups as that after a predetermined time there is a decrease in the pH of the image layer from about 12 to 14 to at least about 11, preferably to about 5 to 0.

The effect of the polymeric acid should of course be regulated in such a way that that neither the development of the negative nor the transfer of the image dyes is disturbed will. For this reason, the pH of the image layer is kept to about 12 to 14 gdalt, until the positive dye image has formed, whereupon the pH value very quickly is reduced to the desired final value.

The inert spacer layer of U.S. Patent 3,362,819, e.g. or contains gelatin, is used to control the timing of the decrease in pH through the polymeric acid layer. This delay is said to be a function of the speed with which the alkali diffuses through the inert spacer layer.

The use of layers to control diffusion in silver transfer processes, e.g. as retardation layers to control a neutralizing layer also known, e.g. from U.S. Patent 3,772,025.

The main object of the invention is to create novel layers for diffusion control in photographic products and diffusion transfer processes, wherein the control layers allow diffusional transfer of a reagent to or through a layer of a photosensitive component or a positive component a diffusion transfer film unit.

Furthermore, according to the invention, products for color photographic Diffusion transfer processes are made available that use an intermediate layer contained in a light? finite element that allows the diffusion of a soluble made dye image-forming material through the interlayer to after Substantially prevent the lapse of a predetermined time.

Furthermore, according to the invention, an intermediate layer is to be created, that from a state in which they are for the solubilized dye image-forming material is practically impermeable, quickly changes into a state in which it is practically permeable to this material.

Furthermore, an intermediate layer of a polymer should be made available both, which are initially impermeable to the solubilized dye-image-forming material and then after a predetermined, short time after contact of the intermediate layer with an alkaline developing composition that contains the dye-image-forming material makes soluble and transported through the intermediate layer, becomes permeable.

Furthermore, according to the invention, products for photographic diffusion transfer processes are intended are made available that have a neutralization system to reduce the pH value of an aqueous-alkaline developer composition, the neutralization system contains a neutralizing layer and a retardation layer that contribute to the neutralizing Layer is arranged so that the developer composition first through the retardation layer must diffuse through before they come into contact with the neutralizing layer comes, with the delay layer being able to quickly come out of a handy transition from an alkali-impermeable state to a practically permeable state.

Furthermore, a polymeric top layer for an image receiving element is intended be made available that quickly from one for the developer liquid impermeable state changes into a permeable state.

Other purposes of the invention will in part, in part, be self-evident also from the description below.

The invention is illustrated by the drawing. They show: FIG. 1 a section through a photographed film unit with layers according to the invention to steamer the diffusion; Fig. 2 is a section through an image receiving element with a retardation layer according to the invention for controlling the diffusion; Fig. 3 shows a model arrangement for determining the “holding time” of the intermediate layers according to the invention; and Figure 4 is a graph of dye density as a function of time in a system with an intermediate layer according to the invention.

It has been found that polymerization products of monomers which subject to ß-elimination in an alkaline environment for timing purposes suitable for diffusion in diffusion transfer photographic film units are. The control layers produced from these polymerization products The diffusion can be used as intermediate layers or top layers in photosensitive Elements as well as layers to control diffusion, e.g. as retardation layers or cover layers are formed in image receiving members. These polymers are subject to ß-elimination before significant swelling occurs, whereby the ß-elimination and the swelling are prerequisites for certain substances, those in an aqueous-alkaline Soluble developer liquid are or are made soluble by them, penetrate through them.

The B elimination, the polymers of the diffusion control layers are exposed according to the invention, ensures that after touching the diffusion control layer through the developer the permeability is delayed, whereby the alkali or the soluble or solubilized material is retained; afterward followed by a rapid "release" or opening so that the soluble or solubilized Material can pass through.

The polymers can be viewed as "hold-on release" polymers, which is the diffusion of alkali or substances that are soluble in the developer liquid are or are made soluble by them, over a predetermined period of time, e.g. from less than 5 seconds to more than a few hundred seconds. the Layers according to the invention for controlling diffusion can be used as intermediate layers between silver halide layers that sensitize for different spectral ranges are used, with each emulsion associated with a color imaging material is. For example, they can be used as described in US patents 3,615,422 and 3,421,892, the "hold-on release" polymers used according to the invention instead of the interlayer polymers described there will.

The time for B elimination after contact with the developing liquid as well as for the subsequent hydration should be sufficient to the intermediate layer practically impermeable to the solubilized dye image-forming material to hold up the emulsions between the intermediate layer and the image receiving layer are at least largely developed, but before any significant obfuscation entered the emulsion layer with the greatest fogging rate is.

The layers according to the invention for controlling diffusion can as retardation or spacer layers between those introduced into the film unit alkaline developer and a neutralizing layer, e.g. a polymer Acid layer used to start the pH decrease too control by acting as a practically impermeable barrier to the alkaline developer until the B-Elimineierung has taken place.

The layers according to the invention for controlling the diffusion can can also be used as cover layers, for example as cover layer 19 in FIG 1, With the help of such a top layer, for example, the desired dye transfer by converting a practically dye-impermeable layer into one practically dye permeable layer can be controlled.

Incorporation of double bonds into a molecule with single bonds removes or eliminates atoms or groups of neighboring atoms. When elimination reactions occur with ß-substituted esters, acids, ketones, aldehydes and nitro compounds, these are called ß-eliminations. According to Hendrickson, Cram and Hammond, Organie Chemistry (3rd edition, MeGraw-Hill Book Company, 1970), the electron-withdrawing groups have strong effects on the acid strength on the a-proton, which is removed by a base during the reaction. This 1,2-elimination under basic conditions is very common, as can be seen in Figure 14-3 from Hendrickson, Cram and Hammond given below.

where L is a leaving group, B is a base and -NO2 is a typical activating group. In general, this equation can be stated as follows: wherein Y is an activating group.

Substituents that cause ß-elimination under basic conditions activate are known. The nature of activation in β-eliminations has been suggested by J. Crosby and C.J.M.

Stirling in J. Chem. Soc. (B) 1970, page 671. It was determined, that the resonance stabilization of a carbanion is an important component of the activation is.

It has been found that such a ß-substituted compound in a Polymer can be incorporated to produce a polymer that is alkali-resistant or certain substances that are soluble in an alkaline developer composition or be solubilized thereby, is practically impermeable until through the ß-Elimination bonds are broken, whereby groups are released, which are able to absorb and swell water, so that the polymer for these soluble or solubilized substances become permeable; such a Polymer can be used in the form of a layer to control diffusion, wherein the predetermined delay is a premature diffusion of alkali or soluble or solubilized substances prevented. By setting the molar Proportion or ratio of these B-elimination groups in the polymer as well as through the thickness of the polymeric layer, one can determine a predetermined permeability time as desired for a particular diffusion transfer system.

Referring to the general equation for the B-elimination, the leaving group L is the polymeric structure from which the B-substituted Material is eliminated, or a polymer that has additional grafted groups contains, as it is in the simultaneously filed patent application P (our reference: 3920-I-10.602) is described and claimed.

The ß-elimination can then be represented as follows: where L and R¹ is hydrogen or methyl and Y is one of the groups -SO2W, or -CN denotes, in which W = -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2-N (CH2C6H5) 2; T = -OC2-H5, -CH3, -H, -NH2, -NR2; G = phenyl, methyl or ethyl and R is alkyl, e.g. methyl or ethyl. The ß-elimination can also be represented as follows: where L and R 'and Y have the meanings given above.

In general, the reaction can be represented as follows: where the symbols have the following meanings: R "is the addition polymerization unit of an ethylenically unsaturated alkyl group having 2 to 5 carbon atoms, including the grafting of such an ethylenically unsaturated alkyl group onto a polymeric organic structure; A, E and D are hydrogen, methyl and phenyl, respectively , provided that no more than one A, E, or D can be methyl or phenyl; Y is an activating group as defined above. Typical monomers which provide a β-elimination activating group to their polymerization product are 2-cyanoethyl acrylate , 2-cyanoethyl methacrylate and 2-carbethoxyethyl methacrylate.

Other monomers giving their polymerization products the same functional Provide group are, for example, 2-p-toluenesulfonyl ethyl acrylate and 2-methane sulfonyl ethyl acrylate.

The res @ t # ons using the polymerization product of 2-Cyanäthylaerylat can be represented as follows: The layers according to the invention for controlling the diffusion can contain homopolymers or copolymers, including Prfpf copolymers, as has already been mentioned above.

Mixtures of polymers can also be used.

Contain suitable copolymers for layers for diffusion control in addition to the B-eliminating component, units of comonomers that contain the Impart certain desirable properties to polymers. This can for example modify cohesion or viscosity, film structure and coatability improve or provide a more even flow of fluids or ions. For example, butyl acrylate is suitable for hydrophobing and for controlling the Dye penetration rate. It can also be non-hydrolyzable or crosslinking comonomers are used. Acrylic acid, methacrylic acid, 2-sulfoethyl methacrylate and 2-acrylamide-2-methylpropane sulfonic acid have been found to be useful comonomers proven to ensure that all parts of the diffusion control layer the developer mass in practically the same time and at the same speed let through, so that an even ß-elimination and hydration of the Permeability-setting component is promoted. Ethylene glycolate, a cross-linking monomer, is suitable in the diffusion-controlling layer e.g. as Interlayer for modifying the dye transfer rate the original hold time.

As shown in FIG. 1, layers according to the invention can be used used for diffusion control in a photographic film unit, which contains a light @ p @ indigenous element 20 and an image receiving element @@. the Intermediate layers 13 and 18 are located between the red and green sensitive ones Silver halide emulsion or

between the blue- and green-sensitive silver halide emulsion im photosensitive element. these interlayers and the emulsions with yours associated color imaging material (e.g., developing dyes) are preferred Arranged on a film base 10 in the following order: --hcijt 11 with blue-gray developer dye, red-sensitive silver halide emulsion layer 12, interlayer 13, layer 14 with purple developer dye, green @ sensitive Silver halide emulsion 15, interlayer 10, rail 17 with yellow developer dye and blue-sensitive silver halide emulsion layer 18, on the blue olindicene A top layer 19 can be applied to the silver halide emulsion layer.

The image receiving element 27 of FIG. 1 eflDLit in the order given an image receiving layer 21, a spacing or retarding layer 22, a neutralizing one Layer 25 and a carrier layer 24. The image-receiving layer lies during development close to the photosensitive element.

After exposure to light, the photosensitive element becomes an aqueous alkaline one Developer composition 20 between the photosensitive element and the image receiving element introduced, penetrating the emulsion layers and developing the latent image contained therein sets in motion and a medium for dye diffusion transfer to the image receiving element creates. The substances forming the dye image, those of the unexposed parts assigned to the emulsion layers are, di @ fu @@@ ieren in a manner known per se to the lildempnangselement, As in of US-TS 3 382 819 is read, it is located under the image catch layer a neutralizing splint that contains a polymeric acid to keep the alkali in to neutralize the developer mass @aen a predetermined time.

The retardation or spacer layer of pelymerem material that is located between the image receiving layer and the neutralizing layer, @ is rotten to control the reduction of the pH value, the Senich @ s for diffusion control, which according to the invention contain a B-eliminating polymeric material are at In a preferred embodiment, the intermediate layers 13 and / or 18, It can but also the cover layer 19 is not made of a B-eliminating polymeric material included for diffusion control. In another preferred embodiment the spacer layer 22 is the diffusion control layer according to the invention.

The image receiving element 27 of FIG. 2 is contained in the specified Sequence a carrier layer 28, a neutralizing layer 29, a spacer or retardation layer 30, an image receiving layer 31 and a cover layer 32. During development, the top layer of the image-receiving element overlies the photosensitive element Element closest. In one embodiment of this invention, the top layer is 32 the diffusion control layer which is a B-eliminating polymeric material contains according to the invention.

The "clearing time" required to reduce the pH value can be can be determined using the following system: an image receiving element, , which in the order given is a carrier layer, a polymeric acid layer, the delay layer to be tested and contains a pickling layer, is a @@@ inchern developer with a high pH value, the @nen indicator color contains, which is strongly colored at pH values of eswa 1 @ to 14 and underha @@ about 10 fars on is overdone.

A transparent cover sheet is placed on the E @@ wrapper. The view through the cover film around H @@@ empiangselement appears dark until the Alkali lasts @ the polymeric acid layer is restricted in which the pH value reduced by alkali consumption. Then the indicator color becomes colorless and the system @ "clear". A trained observer can determine when they "clear" begins and when it ends, a 'leaky' delay layer leaves immediately a little alkali passed through the first centennial act and showed no sudden changes at the beginning and at the end of the clarification. A retardation layer with the polymers according to the invention holds back the alkali for a certain time and then allows a very short citrus space for the passage of sufficient alkali to maintain the pH lower below the transition area of the indicator dye.

The clearing time can be determined for an arrangement that is a complete Represents image receiving element, or else for a simplified model arrangement, in which only a retardation layer on the polymeric acid layer on the Pad is applied. The first clarification period is called "clarification by the pickling agent" designated. while the second clarification with the model arrangement as "clarification through the delay layer "is called.

The layer according to the invention for controlling the diffusion, which acts as a cover layer used for an image receiving element is located above the layers made of which the image receiving element is composed. For example, in an image receiving element, that in the order given a carrier layer, a polymeric acid layer, does not contain a spacer layer and an alkali-permeable and dyeable polymer, the layer to control the Diffuses adjacent to the alkali-permeable and dyeable polymeric layer and is farthest from the carrier layer away; it delays the passage of the developer composition and that made soluble by it Substances to the image receiving element.

The ability of the polymeric layers according to the invention to control diffusion, to delay the passage of imaging dyes until the polymer passes through a ß-elimination for the dye has become relatively permeable, can under Using the test arrangement shown in FIG. 3 can be determined. At this In general, dye transfer through the polymeric test material, e.g. Test material for an intermediate layer, determined as a function of time. The "hold-on release" properties of a polymeric test material can be used to Determination of the effectiveness of the material, e.g. as an intermediate layer in a light-sensitive element, can be determined.

Such a test arrangement as well as a suitable house evaluation method are illustrated in Examples 1-15.

The following examples illustrate the invention in a non-restrictive manner Way. The measurements were carried out at room temperature (about 250C), if nothing otherwise is said.

Examples 1-10 On clear film backing 33 (see FIG. 3) was a layer 34 containing about 215.3 mg / m² (20 mg / ft²) of a cyan developer dye having the formula 430.6 mg / m² (40 mg / ft²) of genatine and 16.1 mg / m² (1.5 mg / ft²) of succinaldehyde using a conventional loop coater. Over this layer was applied a layer 35 containing about 2.15 g / m² (200 mg / ft²) of the polymeric material to be tested.

On a clear element 98 with a clear polyester film backing the test elements were applied, and an opaque alkaline developer massevDõ having the composition given below was placed between the polymeric test material layer and the clear element at a gap width of about 0.07 mm (0.0028 inch) introduced: Potassium apdroxide (45% aqueous solution) 22.9 g of lithium hydroxide 0.55 g benzetsiazole 1.53 g b-Broz-p @@ etnyl-4-azabenzimidazole. 0.08 g of 5- @ etny-uracil. 0.82 g ethylenediaminetetracacetic acid 2.27 g bis (2-aminoethyl) sulfide 0.06 g Carbowax (ZC @ 000) 1.5 g colloidal silica 5.05 g 6-benzylaminopurine 1.09 g titanium dioxide 115.23 g of N-phenethyl - @ - pieolinumbronid (50% aqueous solution) 3.91 g of N-benzyl - @ - picelinium bromide 5.09 g (50% aqueous solution) 0.27 g lithium nitrate 4.82 g carbexymethyl hydroxyethyl cellulose Water 100.0 g. The optical reflection density of the developed brobe was over red Light (viewed through the carrier film 55 of FIG. 5) as a function of time continuously using a Macßeth-Ouanta-Log densitimeter with a Read Hewlett-Packard 17505A recorder. This density is composed of Proportions of the dye-generating pild material remaining in the dye layer and the dye imaging material in the polymeric test layer.

The titanium dioxide in the developer mass masks the dye-imaging agent Material in the layer of developer compound.

A typical density curve as a function of time is given in Fig. 4, where the symbols have the following meanings: T1 is the time to dissolve the dye image forming material; t2 is the total time while the image-generating material through the polymer interlayer is withheld; DO is the density after the dye image-forming agent begins to dissolve Materials; Df is the density after transfer of the dye through the intermediate layer. The slope of the linear section between A and B is called the speed calculated from the change in density.

Values for t1, t2 and for the slope are below for the following "Captive-release" polymer systems according to the invention indicated: 1,100 parts by weight 2-Cyanäthylaerylat, mixed with 100 parts by weight of a 95.5 / 4.5 copolymer Diacetone acrylamide and acrylic acid, then polymerized.

2. 35 parts by weight of 2-cyano ethyl ether mixed with 65 parts by weight of a 95.5 / 4.5 copolymer of diacetone acrylamide and acrylic acid, then polymerized.

3. A 47.5 / 50 / 2.5 interpolymer of diacetone acrylamide, 2-cyanoethyl acrylate and acrylic acid.

4. A 63/35/2 interpolymer of diacetone acrylamide, 2-cyanoethyl acrylate and acrylic acid.

5. An 85/10/2/3 interpolymer of butyl acrylate, 2-cyanoethyl acrylate, Methacrylic acid and 2-acrylamido-2-methylpropane sulfonic acid.

6. an 85/10/2/3 interpolymer of butyl aerylate, 2-cyanoethyl aerylate, Methaeryl acid and 2-sulfoethyl methaerylate.

7. 95 parts by weight of 2-cyano ethyl acetate mixed with 100 parts by weight of a 99.25 / 0.75 copolymer of 2-cyanäthylaerylamid and aerylic acid, then polymerized.

8. A 63/35/2 interpolymer of diacetonaerylamide, 2-carbethoxyethyl methacrylate and aenic acid.

9. A 63/35/2 interpolymer of diacetone acrylamide, 2-cyanoethyl methacrylate and acrylic acid.

10. 100 parts by weight of a 94/6 copolymer of diacetone acrylamide and acrylic acid mixed with 100 parts by weight of a 63-35 / 2 intrpolymer of diacetonarylamide, 2-cyanoethyl methacrylate and acrylic acid.

All proportions of the interpolymer component are based on weight. Sample t1 @ 2 slope 1 2 28 404 2 3 22 522 3 5 15 280 4 5 580 5 0 11 675 6 10 16.5 737 7 0 23 250 3 0 2 200 9 7 14 870 10 1 18 525 The table above shows that, according to the invention, a considerable holding time is achieved before the solubilized, dye-image-forming sodium is released, and that the dye is released over a relatively short period of time.

The hold time is longer at around 7 ° C (450F) and shorter at around 350C (950F), which goes in parallel with the development time.

For example, in the above sample, No. 2 is t2 215 sec. at 7 ° C (slope 87) and 11 sec. at 350C (slope 654).

Examples 11-12 There were test elements as according to the examples 1 to 10 produced. A second see-through element with a clear polyester film backing was placed on the test elements to prepare laminates and an opaque one alkaline developer requirements mi. the composition given below between the polymeric material and the uppermost layered element with a layer thickness of about 0.07 mm (0.0028 inch) introduced: potassium hydroxide (45% aqueous solution) 13.63 g cesium hydroxide (50% strength aqueous solution) 10.65 g benzotriazole 1.18 g 5-hydroxyazabenzimidazel 0.118 g 6-bromo-5-methyl-4-azabenzimidazole 0.059 g 2-methylimidazole 0.42 g sodium carbozimethyl cellulose 4.43 g titanium dioxide 59.27 g N-phenethyl - @ - picolinium bromide (50% aqueous solution) 4.2 g water 100 g The time (t) it takes for the dye to pass through the polymer mate rial was required by ongoing determination of the optical Density of the dye through the top clear element using determined by the densitometer given in Examples 1 to 10.

The values for t (in sec) are below for the following "hold-on release" polymer systems stated according to the invention: 11. 2 parts by weight of an 85/10/3/2 internal polymer from butyl acrylate, 2-cyanosyl acrylate, 2-sulfoethyl methacrylate with 1 part by weight of a 94/6 copolymer from butyl acrylate.

12. am 81/10/2/3-Interpelymer from 2-Cyanoäthylaerylat, Methaeryls @@ re and 2-aerylanide-2-methylpropane-sulfenenic acid 13. an 89/6/2/3 interpolymer made from butyl anylate, 2-Cyanäthylaerylat, Methaerylsä @ re and 2-Sulphoäthylmethaerylat.

14. 85 parts of a 68/10/2 / @ - interpolymer of butyl aerylate, 2-cyanoethyl metharylate, 2-Sulfoäthylmethaerylat and Äthyleneglykoldimethaerylat, polymerized to seed germs from 15 parts by weight of butyl acrylate.

15. An 85/10/2/3 interpolymer of butyl aerylate, 2-cyanoethyl aerylate, Methacrylic acid and 2-sulfoethyl methacrylate.

Sample 11 70 12 30 13 12 14 13 15 120 Although the value @ indicates the time until the solubilized dye image-forming material adheres to the image-receiving layer it also includes the time it takes for this material to pass through the alkaline developer mass is required, i.e. a time component that is associated with the layer thickness of the alkaline developer composition is related.

The relative proportions of the components of the developer composition can of course can be changed upon request. For example, the individual protective agents, alkalis, Silver halide solvents, etc. are exchanged; furthermore, retarders can be used respectively. Accelerators can be added. Also the concentration of the individual components zenn can be varied over a wide range.

Examples 1o - 19 no Coating a clear polyethylene terephthalate film underlay with a Approximately 0.1 mm (4 mil) thick with the layers below in one Image receiving component processed: 1. As a polymeric acid layer, the partial Butyl ester of the polyethylene / maleic anhydride copolymer mixed with about 10 Weight percent polyvinyl butyral; Coating weight about 26.91 g / m² (2,500 mg / ft2); 2. one Retardation layer with polymeric substances, as explained in more detail below are; and 3. as the polymeric image receiving layer, a mixture of 6 parts by weight of polyvinyl alcohol, 3 parts by weight of poly-4-vinylpyridine and 1 part by weight of a graft polymer 4-vinylpyridine-vinylbenzyltrimethylammonium chloride on hydroxyethyl cellulose; Order weight about 3.23 g / m² (300 mg / ft²). These elements are denoted by (a).

For comparison, test elements were produced which did not contain any polymeric image-receiving layers over the retardation layers. These elements are denoted by (b) Delay shift shower time (sec) Example material order weight Beginning end mg / m² / mg / ft² Control (a) I 5.38 500 180 210 (b) I 4.38 500 60 87 16 (a) II 2.69 250 215 245 16 (b) II 2.69 250 60 58 17 (a) II 5.38 500 290 325 17 (b) II 5.38 500 92 105 18 (a) III 5.38 500 33 40 18 (b) III 5.38 500 25 29 19 (a) III 2.69 250 25 32 19 (b) III 2.69 250 15 20 Here, I denotes a 60/20/4/6 interpolymer composed of butyl acrylate, diacetone acrylamide, styrene and methaeric acid, mixed with 9% by weight of polyvinyl alcohol; II denotes inoculants made from 100 parts by weight of an 87.5 / 2 / 0.5 interpolymer as diacetonaeryl amide, aerylic acid and 2-arylamido-2-methyl-porpanesulfonic acid (sodium salt), around which 49 parts by weight of 2-cyanoethyl acrylate are polymerized; III means a 63/35/2 interpolymer of diacetone acrylamide, 2-cyanoethyl acrylate and derylic acid.

A developer compound with the following composition: 100 g water 4.02 g hydroxyethyl carboxymethyl cellulose 4.15 g potassium hydroxide solution (50%) 1.12 g benzotriazole 0.50 g thymolphthalein was added between the polymeric test material layer and the clear element in the layer thickness of about 0.07 mm (0.0028 inch) introduced. The transit time (sec), i.e.

the time in which the color of the laminate from blue after turned over without color, is a measure of the passage time of the developer mass through the retardation layer and for the reaction with the polymeric acid for reduction of the pä value. the times are @@@ "start" when the laminate begins, to be clarified and with "end" when the laminate is practically clarified.

Examples 20-27 On a clear polyethylene terephthalate film base with a layer thickness of about 0.1 µm (4 mils) was the partial butyl ester des Polyethylene / maleic anhydride copolymers mixed with about 10 parts by weight a / @lyvinyl butyral was applied at a coating weight of about 2.69 g / m² (2500 mg / ft²). The delay layers and bill receiving layers given below are applied to this layer applied with the specified application weights. The breakthrough time became like stated above, measured.

Retardation layer Image receiving layer Penetration time (sec) Example material order weight Material order weight Beginning end g / m² mg / ft² g / m² mg / ft² 20 A 2.15 200 21 A 2.15 200 D 5.38 500 54 58 22 B 2.15 200 31 23 B 2.15 200 D 4.38 500 62 24 C 6.45 600 41 48 25 C 10.77 1000 41 48 26 C 6.45 600 D 5.38 500 80 92 27 C 10.77 1000 D 5.38 500 80 110 A denotes inoculants of a 50.7 / @@@@ / @@ interpolymer composed of butyl aerylate, 2-cyano ethylaesylate, ethylene glycol dimethaerylate, aerylic acid and serel, in order to polymerize a 10/3 mixture of diacetonaerylamide and aerylaic acid. The pH value of A is 2.6; B denotes the material from A to which sufficient potassium hydroxide has been added to bring the pH to 8.0; C denotes a 59/40/1 inberpolymer composed of diasetonaeryl amide, 2-cyano ethylaerylate and aerylic acid; D means a graft copolymer of 4-vinylpyridine and vinylbenzyl-trimethylammonium chloride on polyvinyl alcohol.

Claims (20)

Graft polymers as layers for controlling diffusion in photographic products PATENT APPLICATION Photographic diffusion transfer film unit, comprising: a) a photosensitive element with at least one photosensitive silver halide emulsion layer to which an image-forming material which is soluble and diffusible in a developer composition is associated; b) an image receiving element; c) means for distributing an alkaline developer composition in the film unit; and d) a layer for controlling diffusion in the photosensitive element and / or in the image-receiving element; characterized in that the diffusion control layer is a polymerisation product of a monomer which is subject to B-elimination in an alkaline medium, the polymerisation product being repeating units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D methyl or Can be phenyl; and Y is an activating group. 2. Film unit according to claim 1, characterized in that the photosensitive Element contains at least two silver halide emulsion layers, one of which is in assigned to a developer composition soluble and diffusible image-forming material and that the diffusion control layer is one between the silver halide emulsion layers represents arranged intermediate layer. 3. Film unit according to claim 1, characterized in that the layer represents a cover layer in the photosensitive element to control the diffusion. 4. Film unit according to claim 1, characterized in that the layer to control the diffusion is present in the image receiving element and preferably represents a retardation layer or a top layer of the image receiving element. 5. Film unit according to one of claims 1 to 4, characterized in that that the imaging material is a dye developer. 6. Film unit according to one of claims 1 to 5, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2 N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NR2; G is phenyl, methyl, or ethyl; and is methyl or ethyl. 7. Film unit according to one of claims 1 to 6, characterized in that that the polymerization product poly (2-cyanoethyl acrylate), poly (2-cyanoethyl methacrylate) and / or poly (2-carbethoxyethyl methacrylate) is. 8. Film unit according to one of claims 1 to 7, characterized in that that the polymerization product additionally contains a non-hydrolyzable comonomer and / or Contains units of a crosslinking comonomer. 9. A photosensitive element for diffusion transfer photographic processes containing; a backing layer; at least two selectively sensitized silver halide emulsion layers which are applied to the carrier layer, each emulsion layer being assigned a dye-image-forming material which is soluble and diffusible in the developer composition; and an intermediate layer disposed between at least two silver halide emulsion layers; characterized in that the intermediate layer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium, the polymerisation product having recurring units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D methyl or Can be phenyl; and Y is an activating group. 10. Photosensitive element according to claim 9, characterized in that that there is a red-sensitive silver halide layer in the order given, associated with a cyan dye image forming material; a green-sensitive one Silver halide layer which is a purple dye image-forming material assigned; and a blue-sensitive silver halide layer which is a yellow one Dye-generating material is assigned. 11. Photosensitive element according to claim 9 or 10, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2-N (CH2C6H5) 2; T is -OC2H5'-CH3, -H, -NH2, -NR2; G is phenyl, methyl, or ethyl; and R is methyl or ethyl. 12. Photosensitive element according to one of claims 9 to 11, characterized in that the polymerization product poly (2-cyanoethyl acrylate), Poly (2-cyanoethyl methacrylate) and / or poly (2-carbethoxyethyl methacrylate) represents. 13. Photosensitive element according to one of claims 9 to 12, characterized in that the polymerization product is additionally a non-hydrolyzable Contains comonomer and / or units of a crosslinking comonomer. 14. A photosensitive element for diffusion transfer photographic processes comprising: a support layer; at least one light-sensitive silver halide emulsion layer which is applied to the carrier layer, the emulsion layer being assigned a dye-image-forming material which is soluble and diffusible in the developer composition; and a top layer; characterized in that the top layer is a polymerisation product of a monomer which is subject to B-elimination in an alkaline medium, the polymerisation product having recurring units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenic; unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D being methyl or phenyl; and Y is an activating group. 15. Photosensitive element according to claim 14, characterized in that that on the carrier layer at least two selectively sensitized silver halide emulsion layers are upset. 16. Photosensitive element according to claim 15, characterized in that that the selectively sensitized silver halide emulsion layers in the specified Order a red-sensitive silver halide layer, followed by a blue-green one Associated therewith dye imaging material; a green-sensitive silver halide layer, associated with a purple dye image forming material; and a blue-sensitive silver halide layer which forms a yellow dye image Material is assigned, contains. 17. Photosensitive element according to one of claims 14 to 16, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2 -N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NR2; G is phenyl, methyl, or ethyl; and R is methyl or ethyl. 18. Photosensitive element according to one of claims 14 to 17, characterized in that the polymerization product poly (2-cyanoethyl acrylate), Represents poly (2-cyanoethyl methacrylate) and / or poly (2-carbäthxyäthylmethacrylat). 19. Photosensitive element according to one of claims 14 to 18, characterized in that the polymerization product additionally units one non-hydrolyzable comonomer unomen and / or units of a crosslinking comonomer contains. 20. A photosensitive element for diffusion transfer photographic processes comprising: a support layer; at least two selectively sensitized silver halide emulsion layers which are applied to the carrier layer, each emulsion layer being assigned a dye-image-forming material which is soluble and diffusible in the developer composition; and an intermediate layer arranged between at least two silver halide emulsion layers, characterized in that the intermediate layer is a polymer mixture, of which at least one polymer is a polymerisation product of a monomer which is subject to B-elimination in an alkaline medium, the polymerisation product repeating units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D methyl or Can be phenyl; and Y is an activating group. 21. A photographic film unit in the form of a combination of a photosensitive element and an image receiving element for diffusion transfer comprising: a support layer; at least two selectively sensitized silver halide emulsion layers which are applied to the carrier layer, each emulsion layer being assigned a dye-image-forming material which is soluble and diffusible in the developer composition; and an intermediate layer disposed between at least two silver halide emulsion layers; and an image-receiving layer which is permeable and dyeable for an alkaline developer composition; characterized in that the intermediate layer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium, the polymerisation product being repeating units of the formula contains, in which the symbols have the following meanings: R "is the addition polys.erizationss of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms' A, D and E are hydrogen, ethyl and phenyl, with no more than one A, E or D Can be methyl or phenyl; and Y is an activating group. 22. Film unit according to claim 21, characterized in that the Image-receiving element contains a carrier layer on which the alkaline developer composition permeable and dyeable to form a dye image forming material Image-receiving layer is applied, wherein the Hild-receiving element at least is attached to and overlying an edge of the photosensitive element so that the backing of each element is the outer ends of the overlying structure form. 23. A film unit according to claim 22, wherein the photosensitive element is, in the order given, a support layer; a red sensitive silver halide layer having associated therewith a cyan dye image-forming material; an intermediate layer; a green-sensitive silver halide layer having associated therewith a purple dye image-forming material; a wide intermediate layer; and a blue-sensitive silver halide layer to which a yellow dye image of one of the material is assigned, characterized in that a polymerization product of a monomer is contained in both intermediate layers, which is subject to B-elimination in an alkaline medium, the polymerization products being repeating units of the formula contain, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D methyl or Can be phenyl; and Y is an activating group. 24. Film unit according to claim 22 or 23, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2 -N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NT2; G is phenyl, methyl, or ethyl; and R is methyl or ethyl. 25. Film unit according to one of the claims 21 to 24, characterized in that that the polymerization product poly (2-cyanoethyl acrylate), poly (2-cyanoethyl methacrylate) and / or poly (2-carbethoxyethyl methacrylate) is. 26. Film unit according to one of claims 21 to 25, characterized in that that the polymerization product additionally Einn @@@ a non-hydrolyzable comonomer and / or contains units of a crosslinking comonomer. 27. A photographic film unit in the form of a combination of a photosensitive element and a diffusion transfer image receiving element comprising: a support layer; at least two selectively sensitized silver halide emulsion layers which are applied to the carrier layer, each emulsion layer being assigned a dye-image-forming material which is soluble and diffusible in a developer composition; an intermediate layer disposed between at least two silver halide emulsion layers; and an image-receiving layer which is permeable to the alkaline developer and can be dyed, characterized in that the intermediate layer is a polymer mixture, of which at least one polymer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium, the polymerisation product having recurring units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylenically unsaturated alkyl group with 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, with no more than one A, E or D methyl or Can be phenyl; and Y is an activating group. 28. An element for diffusion transfer photographic processes comprising: a support layer; a polymeric acid layer; and a further polymeric layer, characterized in that the further polymeric layer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium and is practically impermeable to the developer until the B-elimination has taken place, the polymerisation product having recurring units the formula contains, in which the symbols have the following meanings: "is the addition polymerization pre @@ kt of an ethylenically unsaturated alkyl group with 2 to 5 k @@@ len @ teffatomen; A, D and E are hydrogen, methyl and plenyul, with no more than an A, E or D can be methyl or phenyl; and Y is an activating group. 29. Element according to claim 28, characterized in that there is a contains alkali-permeable and dyeable image-receiving layer. 30. Element according to claim 28 or 29, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -MR2 -N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NR2; G is phenyl, methyl, or ethyl; and R is methyl or ethyl. 31. Element according to one of claims L to 30, characterized in that that the polymerization product poly (2-cyanoethyl acrylate), poly (23-cyanoethyl methacrylate) and / or poly (2-carbethoxyethyl methacrylate) is. 32. Element according to one of the speeches 28 @is 31, characterized in that that the polymerization product additionally has units of a nint hydrolyzable comonomer contains. 33. Element according to one of claims 28 to 32, characterized in that that the further polymer layer acts as a retardation layer between the polymer Acid layer and the image-receiving layer and / or as a top layer over the image-receiving layer is arranged. 34. Image receiving element for photographic diffusion transfer processes, comprising a support layer; a polymeric acid layer; a polymeric layer; and an alkali-permeable and dyeable image-receiving layer, characterized in that the polymeric layer is a polymer mixture, of which at least one polymer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium, the polymerisation product having recurring units of the formula contains, in which the symbols have the following meanings: R is the addition polymerization product of an ethylenically unsaturated alkyl group having 2 to 5 carbon atoms; A, D and E are hydrogen, methyl and phenyl, it being possible for no more than one A, E or D to be methyl or phenyl; and Y is an activating group. 35. Image receiving element according to claim 34, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2-N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NR ,; G is phenyl, methyl, or ethyl; and R is methyl or ethyl. 36. Image receiving element according to claim 34 or 35, characterized in that that the polymerization product poly (2-cyanoethyl acrylate), polu- (2-cyanoethyl methaerylate) and / or poly (2-carbathoxyethyl methacrylate) represents. 37. Image receiving element according to one of claims 34 to 36, characterized characterized in that the polymerization product has additional units enec non-hydrolyzable contains comonomers and / or units of a crosslinking comonomer. 38. Image receiving element according to one of claims 34 to 37, characterized characterized in that the polymeric layer with the polymer mixture as a retardation layer between the polymeric acid layer and the image-receiving layer and / or as a top layer is arranged over the image receiving layer. 39. A photographic film unit comprising a combination of a photosensitive element and an image-receiving element for diffusion transfer, the image-receiving element comprising: a support layer; a polymeric acid layer; a polymeric layer; and an alkali-permeable and dyeable image-receiving layer; characterized in that the polymeric layer is a polymerisation product of a monomer which is subject to β-elimination in an alkaline medium, the polymerisation product being repeating units of the formula contains, in which the symbols have the following meanings: R "is the addition polymerization product of an ethylene is. unsaturated alkyl group with 2 to 5 carbon atoms; A, D and z are hydrogen, methyl and phenyl, with no more than one A, E or D being methyl or can be phenyl; un Y is an activating group. 40. Film unit according to claim 39, characterized in that the activating group is one of the groups represents, in which the symbols have the following meanings: W is -C6H5CH3, -CH3, -OC2H5, -C6H5, -NR2-N (CH2C6H5) 2; T is -OC2H5, -CH3, -H, -NH2, -NR2; G is phenyl, methyl, or ethyl; and R is metal or ethyl. 41. Film unit according to claim 39 or 40, characterized in that the polymerization product poly (2-cyano ethyl ether), polu- (2-cyano ethyl methacrylate) and / or poly (2-carbethoxyethyl methacrylate) is 42. r i purity according to a of claims 39 to 41, characterized in that the polymerization product additional units of non-hydrolyzable comemers and / or units of a contains crosslinking comonomer. 43. Film unit according to one of claims 39 to 42, characterized in that that the polymeric layer of the image receiving element acts as a retardation layer between the polymeric acid and the image-receiving layer and / or as a top layer is arranged over the image receiving layer. 44. A photographic film unit in the form of a combination of a photosensitive Element with an image receiving element for diffusion transfer, wherein the photosensitive element contains: a support layer for the photosensitive Element; at least two selectively sensitized silver halide emulsion layers, which are applied to the carrier layer, each emulsion layer having an in assigned to the developer composition soluble and diffusible color image-forming material is; an intermediate polymeric layer; and an alkali-permeable and dyeable image-receiving layer. characterized in that the polymeric intermediate layer is a polymerization product of 2- (Cyanä.tiylacrylat) and the image-receiving element on a carrier layer polymeric acid layer and a polymeric layer made of poly (2-cyanoethyl acrylate) contains.