GB2042752A

GB2042752A - Mordant layer for dye images

Info

Publication number: GB2042752A
Application number: GB8002769A
Authority: GB
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1979-02-06
Filing date: 1980-01-28
Publication date: 1980-09-24
Also published as: FR2448735A1

Abstract

A receiving element for transferred dyes is provided which comprises a support having coated thereon a water-permeable binder layer in which is dispersed a layer substantive surface active agent having at least one hydrophobic group containing at least 12 carbon atoms and at least one sulphate or sulphonate group. The receiving element may be incorporated in photographic material which contains at least one light sensitive layer.

Description

SPECIFICATION Mordant layer This invention relates to receiving elements for transferred dyes and in particular cationic dyes.

Receiving elements for transferred dyes are of use in dye diffusion transfer processes in photography where dyes are generated imagewise in one layer of the photographic assembly and diffuse to a layer of a dye receiving element where they are mordanted to form a layer of a dye image. In such a process the receiving element may be attached initially to the remainder of the photographic assembly and may, or may not, be separable therefrom after the dye image has been formed therein. Alternatively, the receiving element is not integral with the remainder of the photographic assembly but is held in face-to-face relationship with it in use to enable the diffusing dye to diffuse from the photographic assembly to receiving element which is then removed from contact with the photographic assembly.

Receiving elements are also of use for certain dye imbibition processes in which a dye is transferred to a receiving element in an imagewise manner for example, via an image stencil or from a gelatin image matrix. Such imbibition process may be used in the production of colour positive duplicate film prints.

Receiving elements for both diffusion transfer processes and imbibition processes usually comprise a base on which is coated a dye mordant in a binder. Most mordants which have been used are polymeric substances soluble in water or organic solvents and they are usually coated with the binder as a solution. Such polymers rely on electrostatic and hydrophobic bonding to form a stable dye/mordant complex and these are usually ionically charged polymers of complicated structure made as solution polymers. The polymer must be non-diffusing in the dye receiving layer of the receiving element and difficulties have been experienced in producing suitable solution polymers of sufficiently high molecular weight for all the polymeric material to be non-diffusing in the receiving layer.If the polymeric material is prepared under forcing conditions to obtain higher molecular weight material often the polymer cross-links and thus is incapable of producing a true solution suitable for coating on a support base.

We have now discovered a receiving element for use in mordanting dyes transferred thereto which does not make use of solution polymers as the mordant.

Therefore according to the present invention there is provided a receiving element for transferred dyes which comprises a support having coated thereon a water-permeable binder layer in which is dispersed a layer substantive surface active agent having at least one hydrophobic group containing at least 12 carbon atoms and at least one sulphate or sulphonate group.

By surface active agent is meant a water-dispersible oil-dispersible compound having at least one hydrophilic group and at least one hydrophobic group in the molecule. Surface active agents form micelles in water or oil. Also surface active agents reduce the surface tension of water and act to reduce the interfacial tension of an oil-in-water mixture. Thus may surface active agents are used as emulsifying agents.

A large number of classes of surface active agents may be used in the receiving element of the present invention. In general they exhibit layer substantivity in the water-permeable binder due to the hydrophobic group. Sometimes they are present in the binder as a solid dispersion, sometimes as an oil dispersion or solution. Yet others may be added to aqueous solutions of the water-permeable binder to form micelles in the aqueous coating composition of the water-permeable binder. In this latter case after coating the coating composition on the support the layer is dried. It is not quite clear in what physical state the surface active agent is then present in the layer but it is nevertheless substantive to this layer.

According to a preferred embodiment of the present invention there is provided a receiving element for transferred dyes which comprises a support having coated thereon a water-permeable binder layer in which is dispersed an negatively charged substantive aryl sulphonate compound of the general formula

wherein R, is a hydrogen or halogen atom or an alkyl or alkoxy group wherein the alkyl moiety contains up to 6 carbon atoms or is a hydroxy, aryl or aryloxy group, R2 is a hydrogen or halogen atom, or an alkyl, alkoxy or aralkyl group wherein the alkyl moiety contains up to 6 carbon atoms or an aryl or amido group or it represents the atoms necessary to complete a fused ring system which itself may be optionally substituted by one or more halogen atoms, alkyl, alkoxy or aralkyl groups wherein the alkyl moiety contains up to 6 carbon atoms, or hydroxyl, aryl or aryloxy groups, BAL, is a ballasting group which serves to confer substantivity to the compound to the water-permeable binder, L, is a link group which links BAL, to the aromatic ring, BAL2 is a ballasting group which serves to confer substantivity to the compound to the water-permeable binder and is optionally different from BAWL" L2 is a link group which links BAL2 to the aromatic ring, n is O or 1 and M# is a cation.

In the compounds of formula (1) BAL1 and BAL2 are both hydrophobic groups, at least one of them should contain at least 12 carbon atoms, preferably 12 to 22 or 12 to 18 carbon atoms.

Preferably in formula (1) M# is a sodium or potassium ion.

Preferably in formula (1), n is 0 that is to say there is only one ballasting group present in the compound.

BAL, is preferably either an alkyl group having at least 12 carbon atoms or is an aromatic ring (preferably a phenyl ring) carrying at least two alkyl groups, having from 5 to 10 carbon atoms. Another useful ballasting group BAL1 is a carbon or nitrogen atom having two cyclohexane substituent groups.

BAL2 if present may be any of the groups as just described for BAL1.

The aryl, aralkyl and aryloxy moieties for R1 and R2 are preferably phenyl, benzyl and phenoxy, further preferred halogens are chlorine and bromine.

Formula (1) covers many compounds which have been described as being of use as photographic colour couplers.

For example formula (1) covers the well-known class of a-naphthol cyan colour couplers of the general formula

and of general formula

where BAL, and M# have the meanings assigned to them above.

Compounds of formulae (2) and (3) may be prepared from known colour couplers of formulae (2) and (3) which do not have the 503e substituent group in the coupling position by sulphonating the colour couplers with sulphuric acid at an elevated temperature.

Such a sulphonation is described in the F.I.A.T. Final report No. 943 on page 66.

An example of a compound of formula (3) is the compound of formula

Formula (1) also covers magenta colour couplers of the pyrazolone type of the general formula

where R1, BAL, and M# have the meanings assigned to them above.

In the compounds of formula (5) the pyrazolone ring is the link group L,. Preferably BAL, is an alkyl group having at least 12 carbon atoms, preferably 12 to 18 carbon atoms.

An example of a compound of formula (5) is the compound of formula

The preparation of this compound is given in the F.l.A.T. Final Report 843 on pages 76 and 77.

Other compounds of formula (5) can be made in an analogous manner using different

compounds as the starting material where R, and R2 have the meanings assigned to them above.

Formula (1) also covers yellow colour couplers of the ,B-ketoester type anilide type, for example yellow colour couplers of the general formula

where M#, L, and BAL, have the meanings assigned to them above and R3 is an alkyl or alkoxy group having from 1 to 4 carbon atoms in the alkyl moiety or a hydrogen or halogen atom.

An example of a compound of formula (7) is the compound of formula

Compounds of formula (8) may be prepared in an analogous manner to the yellow colour coupler TA 521 the preparation of which is set forth in F.l.A.T. Final Report No. 945 pages 74 and 75 using the compound of the formula

as the starting material.

Other useful yellow colour couplers of the ,B-keto-esteranilide type are those of the general formula (9)

where L1, BAL1 and M# have the meanings assigned to them above.

Colour couplers of this type may be prepared in similar manner to the yellow couplers of formula (8) again using the compound of the formula

as the starting material and condensing the compound of the formula

with the compound of the formula

Another class of surfactants of use in the receiving layer of the present invention have the general formula (leo) Hydrophobe-link-sulphonate or the general formula (11) Hydrophobe-link-sulphate Preferably the hydrophobe is an alkyl-aryl group where the alkyl group comprises at least 8 carbon atoms and aryl is a benzene group.

A particularly preferred class of surfactants of formula (10) and (11) are those wherein the link is a polyoxyalkylene chain and preferably a polyethylene oxide chain.

Examples of such surfactants are compounds of formula

(Solumin FP 85 - (Trademark) wherein m is 8.5 and

(Triton X-200 - Trademark) wherein n is 8.

Another class of surface active agents are derivatives of succinic acid having at least one sulphonate substituent group and at least one alkyl group having at least 6 carbon atoms. An example of such derivatives of succinic acid are the compounds of the formula:

where Me has the meaning assigned to it above and R4 and R5 are alkyl containing at least 6 carbon atoms and p is O or 1.

Preferably each alkyl group is an alkyl group having at least 8 preferably 8 to 18 carbon atoms.

However, often when each alkyl group has less then 6 carbon atoms aggregation ensures that the compound is layer substantive.

An example of a compound of formula (14) is the compound of formula

Other derivatives of succinic acid are half-esters of succinic acid. They have the general formula

where R6 is alkyl having at least 8, preferably 8 or 9 carbon atoms and M# is a cation.

An example of such a half-ester of succinic acid is the commercially available disodium ethoxylated nonylphenol half ester of sulpho-succinic acid.

Yet other derivatives of succinic acid are sulpho-succinamates. They may have the general formula

where R7 is an alkyl group having at least 12, preferably 12 to 18 carbon atoms, R8 is a group which comprises a sulphonate substituent group and M" is a cation.

An example of such a sulphosuccinamate is the commercially available tetrasodium N-( 1,2dicarboxyethyl)-N-octadecyl sulphosuccinamate. Another example is di-sodium N-lauryl sulphosuccinamate.

Yet other surfactants of use in the receiving layer of the present invention are simple compounds of the general formula

and of formula

where R9 and R10 are alkyl groups having at least 12, preferably 12 to 18 carbon atoms and M# is a cation.

An example of a compound of formula (19) is the compound of formula

which is known as sodium lauryl sulphate.

Another important class of anionic surface active agents of use in the receiving layer of the present invention are alkyl-aryl-sulphonates of the general formula

and of the formula

where R11 and R12 are alkyl groups having at least 8, preferably 8 to 12 carbon atoms and M# is a cation.

A sample of a compound of formula (21) is the compound of the formula

The compounds of formula (1) may be formulated in the receiving layer using many methods by means of which colour couplers are incorporated into photographic layers. For example the compound of formula (1) may be dissolved in an organic solvent which is water-miscible, e.g. ethyl alcohol, and the organic solvent solution added to an aqueous solution of the water-permeable binder and the solution then coated on to the support base. On drying, a dispersion of the compound of formula (1) will be present in the binder. Another method of forming such a dispersion is to dissolve the compound of formula (1) in an oil and then disperse this oil solution in an aqueous solution of the water-permeable binder using mechanical dispersing means or ultrasonic means.

Those surfactants (or surface active agents) forformula (10) to (21) which are water-soluble or at least water-dispersible are formulated by dissolving (or dispersing) the surfactant in a solution of the water-permeable binder and then coating this aqueous solution on the support. The surfactant is then present as dispersed micelles in the water-permeable binder.

With the less water-soluble surfactants and with some of the water-immiscible surfactants, these may be best dissolved in a water-miscible organic solvent e.g. ethyl alcohol and then adding this solution to an aqueous solution of the water-permeable binding agent and coating on to the support.

Sometimes, however, it is necessary to stabilise the mixelles formed in the aqueous coating solution by adding a small amount of a water soluble surfactant such as sodium lauryl sulphate. With this method as well, the surfactant is also present as dispersed micelles in the water-permeable binder.

Water-insoluble surfactants may be formulated by dispersing the surfactant in an oil and then dispersing this oil solution in an aqueous solution of the water-permeable binder using mechanical means (as the alternative method set forth in connection with the formulation of the compound of formula (1)) or ultrasonic means.

The mechanical means employed may be a high shear mixer.

Suitable oils for forming the dispersions include phosphates such as tricresyl phosphate and other triarylphosphates such as alkyl (C1-C8) substituted phenylphosphates. Further suitable oils are dibutyl phthalate and diethyl lauramide.

The preferred water-permeable binder for use in the receiving layer of the present invention is gelatin. However, the water-permeable binders used or which have been proposed to use in photographic layers may be used, for example casein, albumen, polyvinyl alcohol, polyacrylamide and polyvinyl pyrrolidone.

The desirable properties obtained by using the surface active agents containing a sulphate or sulphonate group in the receiving layer are: (i) A large quantity of mordant can be incorporated into the binder without causing undue increase in the solution viscosity or precipitation. Thus higher dye density and more rapid dye take-up may be achieved.

(ii) There is considerable scope for altering the molecular structure of the mordant. The mordant can be "tailored" to suit the diffusible dye to be captured, thereby optimising the amount of dye bound, and the rate of uptake.

The preferred compounds of formula (1) are the sulphonated colour couplers as hereinbefore described or structurally very similar compounds, which might not in fact act as colour couplers because so much work has gone into the preparation of colour couplers and to their coating as substantive compounds in photographic layers.

The most preferred compounds of formula (1) are the a-naphthol colour couplers of formula (2) because of their ease of preparation and ease of dispersion in the water-permeable binder layers.

A suitable coating weight for the binder on the support is from 10 to 100 mg dim~2.

Suitable receiving elements comprise a layer containing a surfactant as hereinbefore defined coated in gelatin containing from 0.1 to 20, for example 1.0 to 10% of the surfactant (by weight), preferably 2.0 to 5% of the surfactant coated on a support.

The support for the receiving element may be a film base on which is coated the receiving layer containing the surfactant or it may be a paper base on which is coated the receiving layer. However, any other base normally used as a photographic support may be used for example glass. If the receiving elements is to be used in an imbibition process to achieve an artistic effect any type of rigid base may be used such as a metal plate or even wood. It is to be understood that there may be another layer or layers between the receiving layer and the base on which it is coated. Such layers may be for example subbing layers, neutralising layers or timing layers.

The receiving element of the present invention may be used in a photographic colour diffusion transfer process. In this case the receiving element may be an integral part of a photographic assembly which includes at least one light-sensitive layer. Usually the photographic assembly is light exposed, possibly through the base of the receiving element if this is transparent. Thereafter processing fluid is introduced into the assembly, this develops the photosensitive material and at the same time causes an imagewise transfer of at least one diffusible dye which is liberated in the assembly. The diffusible dye migrates to the receiving element where it is mordanted by the layer substantive surface active agent as hereinbefore defined in the receiving layer.In some processes using such a photographic assembly the receiving layer remains integral with the remainder of the photographic assembly although it may be attached along one edge, for example. After imagewise exposure of the photographic assembly the receiving element is placed in face-to-face contact with the remainder of the assembly, processing fluid is placed therebetween and a transfer of at least one dye from the photosensitive part of the assembly to the receiving element takes place. When the transfer of a dye has been completed the receiving element can be removed from contact with the remainder of the photographic assembly.

Thus the invention includes light sensitive photographic assemblies which comprise a receiving element as hereinbefore defined.

The receiving element of the present invention is also of use in an imbibition transfer process for example the process wherein a relief gelatin image is formed on a matrix. This relief image is dyed with a cationic dye and the matrix is then pressed into contact with the receiving element so that the dyed gelatin is in face-to-face contact with the receiving layer. Dye is then transferred to the receiving layer and is there mordanted.

Various other dye imbibition processes, in which the receiving element of the present invention can be used, are known, including a process in which the dye is transferred to the receiving layer through a stencil or imaged silk screen.

The receiving elements of the present invention can be used in any cationic dye transfer process, even to colour overall the receiving layer.

The following examples will serve to illustrate the invention.

EXAMPLE 1 Cationic dyes which may be used to demonstrate the mordanting capabilities of the receiving elements of the present invention include phenosafranine and other well known cationic dyes of the following formulae:

A receiving element was prepared by coating sequentially onto 190 microns thick white pigmented cellulose acetate photobase the following layers: Layer 1 Compound of formula

(dissolved in 5 ml ethanol) 0.5 g Deionised gelatin solution (10%) 20 ml Surfactant of formula 2 ml

Water 30 ml Layer 2 Deionised gelatin 2g Glyoxal solution (10% w/v) 0.5 ml Water 98 ml A A gelatin relief image was produced on Kodak Matrix film (Kodak Trademark) using tanning development.The matrix was soaked for 5 minutes at 250 in an acidic solution of the dyestuff of formula (101) (10-3M pK- 1.0). The dyed matrix was then pressed, face down, onto a sample of the receiving sheet, prepared as above. The two sheets were kept in register and rolled together on a firm surface for one minute. After separation, the receiving sheet was washed in running water for 30 seconds. A clear red image of the matrix could be seen by reflection. This image could not be removed or blurred by washing in water.

EXAMPLE 2 A receiving element was prepared by coating sequentially onto 100 microns thick clear colourless polyester photobase the following layers: Layer 1 A dispersion of the compound of formula

in gelatin prepared by the following method.

A solution of this compound in 50 g of an alkyl substituted triphenyl phosphate, was used in the following formulation: Oil solution as described above 2 9 10% deionised gelatin solution 20 g 50% solution of the surfactant of formula (109) 1 g The mixture was dispersed ultrasonically for 2 minutes, then 1 5 mt water was added slowly, whilst continuing the ultrasonic treatment.

Layer 2 As layer 2 in Example 1.

The receiving element so produced was tested by dye imbibition using the dyestuff of the formula (101). A clear red image was produced which could be viewed by transmission, 'and which was resistan to washing in water.

EXAMPLE 3 A receiving element was prepared by coating sequentially onto white polyethylene laminated paper photobase the following layers: Layer 1 As for layer 1 in Example 1, except that the surfactant of formula

Layer 2 As layer 2 in Example 1.

The receiving element so produced was tested by imbibition as described in Example 1 except that the dyestuff of formula (102) is used. A clear blue dye image was produced which could be viewed by reflection, and which was resistant to washing in water.

EXAMPLE 4 1. Formulation of anionic surface active agents as oil dispersions A saturated solution of the wetting agent (as listed below) was prepared by dissolving in a 1:4 mixture of 2,4-di-t-Amyl phenol in ethyl acetate at 600C. (This typically gave a 1% solution).

The following mixture was then made up: 0.75 ml of the above solution 6 ml of 6% gelatin solution 2.65 ml distilled water.

This mixture was treated ultrasonically to form an oil dispersion of mean droplet size < 1 micron.

2. Preparation of receiving layer elements A coating solution was made consisting of: 3.5 ml oil dispersion (described above) 2.0 ml 6% gelatin solution 1.0 ml 1% solution of the hardener of the formula

The solution was then coated onto subbed polyester base, dried and hardened by incubation.

3. The anionic surface active agents The anionic surface active agent used in the receiving elements is given in the accompanying table 1.

4. How tested and results The receiving elements so produced were tested by imbibition as described in Example 1 by using the dyestuff of formula (102). A clear blue dye image was produced in all elements which could be viewed by transmission. The dyes were resistant to washing in water in all cases.

EXAMPLE 5 Use of anionic surfactants as micelles in binder of receiving element 1. Formulation of anionic wetting agents as micelles A coating solution was made as follows: 2.25 ml 2% solution wetting agent in water 5.0 ml 6% gelatin solution 0.5 ml 1% saponin solution 1.0 ml 1% solution of the hardener of formula (112) 1.25 ml distilled water.

2. Preparation of receiving elements The solution was coated on to a subbed polyester base giving a dry thickness of 10 microns. After drying and incubating the coatings were tested.

3. The anionic surface active agents The anionic surface active agents used in the receiving elements as micelles are given in the accompanying Table 2.

4. How tested and results The receiving elements so produced were tested by imbibition as described in Example 1. A clear red dye image was produced in all elements which could be viewed by transmission. The dyes were resistant to washing in water in all cases.

TABLE 1

CHEMICAL NAME STRUCTURE p-Dodecyl bentene sodium C,,H 0 0 su Iphonate sodium Cl2H2s\#/SO3 - Na sulphonate CH3 Dimethyl dodecyl amino propyl CH3-N-CH2-CH2 -c#2-oso3# sulphate I ] --CHq-CH2I C12 H25 CH3 I 0 Dimethyl hexadecyl amino propyl CM3 - N0-+ 2 - CH2 -C H 12 OSLO3 sulphate I cI5H33 G Sodiumoleyl sulphate CH3-(CH2)7-CH ::CH( CH2)6- OSO 3 Na e # Sodium cetyl sulphate CH3 - (CH2)15- OSO3 Na Sodium lauryl sulphate CH3-(CH2)11 -OSO3 .

TABLE 2

CHIEMICAL NAME FORMULA O Q CO, Na Th####ium##,2'dicarI:oxyethyi) I ,2dicarboxyethyl)-1~G\Na Nsoctadecylsulfosuccinate Na S'CH -C - O C1g H37 0 il (OCH2CH2)10-O -C- CH - SO3 Na Disodium ethoxylated nonyl phenol halt ester of sulphosuccinic acid l WJ CH2CO2 Na C9H19 | CgHlg | | CH 2- CO2- C5Hn Sodium diamyl sulphosuccinate # ~ 1 NaO3 SCHCOZ -c5H11 CH2 CO, - C6HI17 Sodium dioctyl sulphosuccinate | # e I Na O3 SCHCo2-CBH17 0 II Sodium dihexyl sulphosuccinate ## oCH2-C- C6H13 H13 I S - CHC - 0C6 H13 Ii 0 I

Claims

CLAIMS 1 A receiving element for transferred dyes which comprises a support having coated thereon a water-permeable binder layer in which is dispersed a layer substantive surface active agent having at least one hydrophobic group containing at least 12 carbon atoms and at least one sulphate or sulphonate group.
2. A receiving element according to claim 1 wherein the layer substantive surface active agent is a negatively charged aryl sulphonate compound of the general formula

wherein R, is a hydrogen or halogen atom or an alkyl or alkoxy group wherein the alkyl moiety contains up to 6 carbon atoms or is a hydroxy, aryl or aryloxy group, R2 is a hydrogen or halogen atom, or an alkyl, alkoxy or aralkyl group wherein the alkyl moiety contains up to 6 carbon atoms or an aryl or amido group or it represents the atoms necessary to complete a fused ring system which itself may be optionally substituted by one or more halogen atoms, alkyl, alkoxy or aralkyl groups wherein the alkyl moiety contains up to 6 carbon atoms, or hydroxyl, aryl or aryloxy groups, BAL, is a ballasting group which serves to confer substantivity to the compound to the water-permeable binder, L, is a link group which links BAL, to the aromatic ring. BAL2 is a ballasting group which serves to confer substantivity to the compound to the water-permeable binder and may be the same as or different from BAL1, at least one of the BAL, and BAL2 groups containing 12 carbon atoms, L2 is a link group which links BAL2 to the aromatic ring, n is O or 1 and M# is a cation.
3. A receiving element according to claim 2 wherein the negatively charged aryl sulphonate compound of formula (1) n is O.
4. A receiving element according to either claim 2 or claim 3 wherein BAL is an alkyl group having at least 12 carbon atoms.
5. A receiving element according to any one of claims 2 to 4 wherein the aryl sulphonate compound is a compound of either the formula

or of general formula

where BAL, and M# have the meanings assigned to them in claim 2 and R is each alkyl of 5 to 10 carbon atoms.
6. A receiving element according to claim 1 wherein the substantive surface active agent is of the general formula (leo) Hydrophobe-link-sulphonate or of the general formula (11) Hydrophobe-link-sulphate
7. A receiving element according to claim 6 wherein the surface active agent of either formula (10) or of formula (11) the link between the hydrophobe and the sulphate or sulphonate is a polyoxyalkylene group.
8. A receiving element according to claim 7 wherein the polyoxyalkylene group is a polyethylene oxide group.
9. A receiving element according to any one of claims 6 to 8 wherein the hydrophobe is an alkylaryl group where the alkyl group comprises at least 8 carbon atoms.
10. A receiving element according to claim 1 wherein the substantive surface active agent is a derivative of succinic acid having at least one sulphonate substituent group and at least one alkyl group having at least 4 carbon atoms.
11. A receiving element according to claim 1 0 wherein the derivative of succinic acid is a compound of the general formula

where M# is a cation and R4 and R5 are alkyl containing at least 6 carbon atoms and p is 0 or 1.
12. A receiving element according to claim 10 wherein the dereivative of succinic acid is a halfester of succinic acid having the general formula

where M# is a cation and R6 is alkyl having at least 8 carbon atoms.
13. A receiving element according to claim 10 wherein the derivative of succinic acid is a succinamate having the general formula

where R7 is an alkyl group having at least 12 carbon atoms, R8 is a group which comprises a sulphonate substituent group and M" is a cation.
14. A receiving element according to claim 1 wherein the substantive surface agent is a compound of general formula (18) R9-SO3#M# and formula (19) R10-OSO3#M# where R9 and R10 are alkyl groups having at least 12 carbon atoms and M# is a cation.
15. A receiving element according to claim 1 wherein the substantive surface active agent is a compound of general formula (21) and of the formula (22)

where R and R12 are alkyl groups having at least 8 carbon atoms and M# is a cation.
16. A receiving element according to any one of claims 1 to 15 wherein the surface active agent is present in the water-permeable binder as micelles or as an oil dispersion.
17. A receiving element according to any one of claims 1 to 16 wherein the water-permeable binder is gelatin.
1 8. A receiving element according to claim 1 7 wherein the coating weight of the water-permeable binder on the support is from 10 to 100 mg/dm2.
19. A receiving element according to claim 18 wherein the gelatin contains from 1.0 to 10% by weight of the surface active agent.
20. A receiving element according to claim 19 wherein the gelatin contains from 2.0 to 5% by weight of the surface active agent.
21. A receiving element according to any of claims 1 to 20 which comprises at least one other layer between the dye mordant layer and the support.
22. A receiving element according to claim 1 substantively as hereinbefore described with reference to the accompanying Examples.