CA1076106A - Photographic dye diffusion transfer process - Google Patents

Abstract

(Abstract of the Disclosure) Useful non-dissusible die-giving compounds for the photo-graphic dye diffusion transfer process are dye sulfonamides derived from enolamines or endiamines or tautomers thereof.
The dye-giving compounds are oxidized by developer oxidation products and subsequently split under the conditions of alkaline development to release diffusible dyes. The compounds are of the following formula

Description

761~)6 This invention relates to a process for the production of colour photographic images on the dye diffusion transfer principle, and to a photographic material suitable for use in this process which contains new, non-diffusible dye-giving compounds.
Among conventional processes for the production . ,, ~ .
of coloured photographic images on the dye diffusion transfer ~-principle, increasing significance has recently been acquired by those processes which are based on the use of non-diffusible dye-giving compounds, from which diffusible - dyes or dye precursor products are split off imagewise during development and transferred to an image-receiving layer.
Dye-giving compounds suitable for this purpose are, ` for example, the non-diffusible colour couplers described in Ger-` ~an patent- 1,095,115 which release a preformed dye9 or a dye k~ ~ ~ formed during colour coupling, in diffusible form duringdevelopment as a result of a reaction with the oxidation product of a colour developer compound eonsisting of a Z0 primary aromatic amine. The choice of the developer compound required is of course limited to colour developers.
In addition, reference is made in this connection to the non-diffusible dye-giving compounds described in German OLS
1,930,215 in which a preformed latent diffusible dye radical is attached through a splittable hydrazone group to a radical rendering the molecule non-diffusible. These compounds cannot be regarded as colour couplers. It has also been found that the choice of developer compounds required for liberating the diffusible dye radical is by no means confined to the usual colour developers, and black-and-white developers,

-2--' . .
, , ~ , .

~C)76~
for example pyrocatechols, are equally suitable instead.
In addition, German OLS 1,772,929 describes non-diffusible -;
coloured compounds with a special group which, during development, enters into an Oxidative ring-closing reaction and, in doing so, releases a preformed dye radical in a diffusible form.
The compounds covered by German OLS 1,772,929 may be divided into two groups. The compounds belonging to the first group ; ~ require, for development, a normal colour developer compound wi~h whose oxidation product they couple and release the pre-~- 10 formed dye radical in diffusible form in a subsequent ring-closing reaction. The compoundsbelonging to the second group are themselves silver halide developers and, accordingly, are -~
able~,~ even in the absence of ~urther developer compounds in ;
the oxidised form, to enter into the above-mentioned ring-`~` closing reaction by which the diffusible dyes are released.
- Finally, reference should also be made at this juncture to the non-diffusible dye-giving compounds disclosed in German OLS 2,242,762. The compounds in question are sulphonamido phenols and sulphonamido anilines which, 20~ after the oxidation reaction which takes place during ;~ development, are split under the influence of the developer ~ -alkali to release diffusible dyes.
The above-mentioned dye-giving compounds all work negatively. In other words, where normal ~negatively ~ :
working) silver hallde emulsions are used, the diffusible ~
: ., :, dye liberated is distributed imagewise in consistency with the negative silver image produced during development.
In order, therefore, to produce positive dye images, it is nec-essary to use direct-positive silver halide emulsions or, alternatively, to apply a suitable reversal process.
',' . '

-3-' '~ .

, 7~ 6 It is diificult to select, irom conventional dye-givmgcompounds, suitable compounds ~hich are . .
~ satisfactory in every respect both in terms of adequate - reactivity and in terms oi adequate stability. They should not release the diffusible dyes during the actual alkaline development step, but only as a result of image-; wise oxidation through the silver halide developed image-wise. On the other hand, the difiusible dyes should be released sufiiciently quickly in the case of imagewise oxidation, in addition to which the diifusible dyes ... . .
have to be rapidly transierred Furthermore, the dyes should be able to be adequately iixed in the image-'~' receiving layer and, last but by no means least, should ;~ show excellent pectral properties and outstanding stability with respect to light ~nd heat.
The ob~ect oi the present invention is to provide new non-diifusible dye-givingcompounds which combine adequate reactivity with the requisite stability and which, above all, enable a choice to be mAde from a number oi compounds with suitably graduated reactivlty through variation Or the splittable group.
The present invention relates to a photographic , . . . .
dye diiiusion transier proce~s for the production of coloured ~mage~, in which a photographic material having at least one photosensitive silver hallde emulsion layer and, associated with that layer, a non-di~iusible dye-givlng compound which~ in oxidised iorm~ is able to ~elease a diiiusible dye in an alkaline developer medium, is exposed imagewise and developed with a silver ~nlide developer~
the silver haIide developer in oxidised iorm oxidising the dye-giving compound which, as a result oi oxidation~
is ~plit by the developer a~kali to produce an imagewise A-G 1315 ~ 4 ~

. .
': ' -. ~,: , . : , . .
. .. . . . .

76~)6 , -, ~: distribution of the liberated diffusible dye, distinguishea ~. by the fact thatthe non-diffusible dye-giving.compound : corresponds to the following ~ormula: .

~ . 1 2 ~3 ` `
. ~ R1 - C = C - NH - S2 - X

in which ~ X represents the radical of a dye or dye precursor, ..
-` 5 R1 represents -OR4 or NHR5 where R4 is hydrogen or a :.
,,~ radical that may be hyd`rolysed under the conditions , ~
of photographic development3 for example an acyl radical, ~ ., ~ and R5 is hydrogen, alkyl, aryl, acyl or a heterocyclic .-- . groupf said alkyl, aryl, acyl and heterocyclic radicals ~ 10 ~ ~ defined for R4 and R5 in.clude such alkyl, aryl acyl ::: and he~erocyclic radicals which together with one of the .. -~,r'. substituents R2 and R3 complete a 5-, 6- or 7-membered heterocyclic ring containing at least one oxygen or nitro~
. ` gen atom; :
;~ 15 R2 represents hydrogen, alkyl, aryl.or a heterocyolic group -including such alkyl, aryl and heterocyclic radicals which . together~with one of the substituents R1 and R3 ¢omplete a 5-J~or ~-membered carbo:cyclic or heterocyclic ring~or a .... . .
nitrogen atom carrying two substituents; the first sub-stituent is a radical selected from the group consisting ,., ~ . . . .
~ of hydrogen7 alkyl, aryl and acyl including suoh alkyl,.
~: aryl and acyl radicals whioh together with R1 complete ~ .a 5-, 6- or 7-membered heterocyclic ring containing at least .... . . ..
one nitrogen atom; the second ~ubstituent is a radical selected ~rom the group consisting of hydrogen and a radical that togéther with R3 co.mpletes a.5-, 6- or 7-membered .~, heterocyclic ring and pre~erably a pyrrol,pyrazole or pyri-. ~-G 1315 ~ 5 ~
. . .

.
.`'~ , .

~- , ....
.. . . . ..... - . , . ... ~ . ,.-~ .

. .

`
107~ 6 done rin8; but the two substituents a~ the nitrogen atom are not both at the same time hydrogen; R3 represents hydrogen, alkyl, aryl, a heterocyclic group, acyl, cyano or a radical that together with one of the substituents Rl and R2 completes a 5-, 6- or 7-membered carbocyclic or heterocyclic ring; at least one of the substituents Rl, R2 and R3 or a heterocyclic or carbocyclic ring ~i completed by two of these substituents carries a ballasting radical, provided, however~ that in the case of carbocyclic ring closure~-by R ~and~R3 there is -neither in the completed carbocyclic ring nor in an aryl group represented by R5 an amino group or a hydroxyl group located in p-position to the -NH of !
Rl-The alkyl radicals represented by or contained in one or more of the substituents Rl, R2 and R3 include straight chain and branchêd radicals with up to 22 carbon atoms such as methyl, ethyl, isopropyl, tert.-butyl, n-butyl~
or octadecyl; the alkyl radicals may carry further substituents such as halo-gen~ hydroxyl~ alkoxy~ carboxyl~ sulfo and sulfonyl groups~ for example alkyl-sulfonyl or arylsul~onyl.

... .
- The aryl radicals represents by one or more of the substituents Rl, ~ -- ~ R2, and R3 may be phenyl or naphthyl groups and may carry further substituents `~ ~ such as halogen, trifluoromethyl, alkyl, alkoxy, al~ylthio, acylamino, acyl, ~

20 carboxyl or sulfo. `

Where not otherwise stated the acyl radicals mentioned above under Rl, R2 and R3 are undçrstood to include acyl radicals derived from an alipha-tic or aromatic carboxylic or sulfonic acids or from carbonic acid or oxalic :
acid mono esters or from carbamic or sulfa~ic acids which may be substituted at the nitrogen with alkyl or aryl. ~
If R4 represents a radical that i9 hydrolysed under the conditions of photographic development~ it may be any alkali labile or hydrolysable group well-kno-~n to those skilled in the art, e.g. acetyl, mono-, di- or trichloro-~` acetyl~ perfluoracyl~ pyruvyl~ alkoxy acyl or nitroben~oyl. The hydrolysable 30 radical R4 may also be a radical which may be present as a substituent in oneof the possible groups for R2 and R3. The radical `:', ' .
.:' ' ' ' :
-6~
:, , . . . , , . , . , .... , . ~ :

1(~76:~6 R2 is , for example, a phenyl radical with, in the o-position, - a carbonyl group tog-cther with which it ~ormally forms a benzoyl radical (R4).
The heterocyclic radicals represented by or contained in one or more of the substitutents R1, R2 and R3 in-~ clude aromatic heterocyclic radicals such as pyridyl, ; furyl, thienyl as well as saturated heterocyclic ra-dicals such as piperidyl~pyrolidyl, morpholyl Any heterocyclic ring in the dye-giving compounds of the present invention which is completed by two of the substituents R1, R2 and R3 may have condensed to it further rings such as a oondensed benzo ringO This may be the case for example if an ar~l group or an acyl group such as benzoyl is represented by or contained in one of the substituents R1, R2 and R3 and completes to~ether with one of the other two substituents a heterocyclic ring. -Examples of heterocyclic rings completed by R1 and R2 are phthalyl, imidazoline,benzimidazoline,benzdiazinone(qu~a-zolinone)~enzoxazinon, benzthiazole and benzoxazole~ Examples .
of heterocyclic rings completed by R2 and R3 are quinolone, pyridone, indole, pyrrole,pyrazole and coumarin. Indole, pyrrole, pyridone and thiazole are examples o~ heterocyclic ~, .
; rings comple~ed by R1 and R3. Examples o~ heterocyclic ri~gs completed by R1, R2 and R3 are fused rings 7 such as pyra-zolobenzimidazo~e or pyrazoloquinazolone ;~ Alternatively to the meanings given above, R2 and together may also form the atoms required to complete a carboEyclic ring, for example with 5, 6 ~r 7 ring membersj!
more especially an aromatic ring, for example a benzene ring, this ring optionally containing other substituents and/or other rings fused thereto. Howe~er, in cases where R2 and R3 complete an aromatic ring, R5 is not an acyl radical.
~Preferred examples of dye-giving compounds of the present ~-G 1~15 ~ 7 ~
. .

. ~ .
~ ~ ~ ' . i ' ' .. . , . , ., . . . . ,, . , . ", , " .

76~06 .' invention are those of the following formula II

7 ~ -NH - So2 - X II

'''' ' ~l ;
' ' 6 ..
' in which R1 is defined as above, R6 represents an aryl such as phenyl or acyl radical, R7 represents an alkyl or alkoxy radical with up to 22 carbon atoms, or an acylamino or arylamino radical;
these radicals may have attached to'them other radicals -which also may be present in the corresponding substi--~ tuents in pyrazolone color couplers, such as alkoxy, '. '~ alkylthio, aroxy, sulfo, carboxyl, acylamino, sulfamyl jO and halogenO
R1 and R6 together may complete a 5- or 6-membered heterocyclic .
.~ ring, and preferably a benzimidazoline or quinazoli-:. -~ none ring.
:, Other preferred examples of dye-giving compounds of the present invention are those of the following formula III
. I

in which R2 represents hydrogen,.alkyl, aryl or a heterocyclic group, and ' R8 represents one.or more substituents selected from the group consisting of alkyl such as methyl, isopropyl or tertiary butyl, 'alkoxy,such as methoxy., halogen such as chloro,~-'sulf-.~ amyl i~ which one or two of the hydrogens on the nitrogen .~.' .
... may be'substituted by alkyl, or sulfo ~.

,i ' . ' ' ' ' ' A-G 1315 - 8 -, , .,.:

.,, . . " . . , , ., ,:, , " ,. . . . .. . . . ... . . . . ... . ...

` 1(~7tii~{)6 The compounds according to the in~en-tion, which are re-ferred to hereinafter as enolamine or endiaminederivatives, may o~ course also be present at leas-t partly in their tauto-meric form and, accordingly may be formulated as such. However, ;~ 5 this does not apply to compounds in which R4 has a meaning .,, other than hydrogen. It is pointed out that the dye-giving ; compounds according to the invention, as intact molecules9 should not diffuse in the layers of the photographic material.
To this end, they contain a ballasting radical, for example in one of the radicals R1, R2 and R3.
e dye-giving compounds may be adequately resistant to dif~usion even in cases where R1, R2 and R3 do not contain ;any relatively long alkyl radicals, because, e~en in this case, the molecule may be sufficiently large, depending upon the dye radical. Otherwise, it is possible to make the dye-~` giving compounds sufficiently resistant to diffusion by se-lecting radicals (R1, R2 and R3) of suitable size.
Ballasting radicals are radicals which enable the compounds according to the invention to be incorporated in non-dif~usible form in the hydrophilic colloids normally used in photographic materials. Preferred ballasting radicals are organic radicals which generally contain straight-chain ~ or branched aliphatic groups and, optionally, also isocyclic, :- heterocyclic or aromatic groups generally containing ~rom 8 to 20 carbo~ atoms. These radicals are attached to the re-~:' maining part of the molecule either directly or indirectly, for example through one of the following groups: -NHCO-, ~ -NHS02-, -NR-, where R is hydrogen or alkyl, -O- or -S-.
; In the present case at least one o~ the substituents R1, R2 and R~ or a heterocyclic ring completed by two of these substi-tuents carries a ballaating radical. The ballasting radical may also contain water-solubllising groups such asj for example, sulpho groups or carboxyl groups which may even be present in anionic ~orm. Since the di~usion properties are governed . ~
., , .,,.. ; . ~ , , , . , ., ~ . .: . ... ..

,'1' ' ., , ' ' ' " ,', ' ' ' ', , ', ', ' " ., ,, ,, ,,' ,.',,~,',.', '. ,"', ., .. . . .. . .
~, : . , ., , : , . . . . . . .

1~76~36 by the size of the molecule o~ the total compound used, it is suf~icient In certain cases~ for example if the ~otal molecule used is large enough, to use even shorter-chain radicals as the ballasting radicalsO

Suitable dye radicals are,basically,the radicals of dyes belonging to any class, providlng they are suificiently diffusible to be able to diffuse through the layers oi the photosensitive material into the image-- receiving layer. For this purpose, the dye radicals may be provided with one or more water-solubilising groups.
~' Suitable water-solubilising groups are, inter alia, `~ carboxyl groups, sulpho groups, sulphonamide groups and aliphatic or aromatic hydroxyl groups. However, the , ~ sulphonamide group remaining in the dye after splitting '" leaves the dye molecule with a considerable tendency ~` towards diffusion in alkaline medium, so that the presence of additional water-solubilising groups is not absolutely essential. Examples of dyes .. ; .
'~ particul~rly suitable for use in the prooess according ` ~ 20 to the invention are azo dyes, azomethine dyes, anthraquinone dyes, phthalocyanine dyes, indigoid dyes, triphenyl methane dyes, and also metal complex dyes and coloured metal complexes.
'~ In the oontext oi the invention, residues o~ dye preoursor~ are the re~idues of compound~ which are converted into dyes during photographic processlng by the usual or by additional processing stages, w~ether ' by'sxidation, by coupling or by liberating an auxochromic ''~' group in a ohromophoric system~ ior example by hydrolysis.
Dye precur~ors corresponding to this dei'inition may be ;
leuco dye~ couplers or even dyes whi¢h are converted , into other dyes during processing. Providing a distinction between dye radioal~ and the radicals of dye precursors is not oi essential significance, dye precursors are also intended to be covered by the generic expression ~dye radical~ u~ed hereinafter.
A-G 1315' - 10 - '~
':
-: .,. ,.. - .. , . , , , : , .... . . . . ... . . ... .

-~,: - ... , , . ,,.,. : .,, ~" . , , , ,. . :. , , 76~ )6 - ~ Formula examples: -~ The following are examples o~ suitable dye-giving - :
:; compounds acc~rding to the invention:

~ 2 ~ N _ N CO-NH~CH3 1-~35C17 ~ Nl~`NH ~ OCH3.HC ~ LN

:, :~ S03H
;;, .
. . . .
:
. . ~ .
r~

-502 ~ NH-COCH3 ~N ~ d ~ OH

; : S03H

.. ~ ~.: ...

3. ~ ~

02-NH ~ l7H35 ; : s~3H ~ . ~ N~ :
HN

!r~
.. 3 .

. A G 1315 - 11. - ` .

" ~ , .
, , . . . .

.. ., ,,, ~., , , , ,, , . , , : , ~ ~076~

`'^` ^ ~NH-COCH3 35 1~ ~N=N
d~ c;~
~: IJ
'' .`' .
~ ', ' .
35 17 ~ NN-COCH3 N = N~3 Cl .. !

CO~ CH~
~'~ 6- ~ ~--~CN2]3--OjC~NH-502 ~N=N~

Cr N NH HO N~

i``: ~ : . .

7 . (~ o ~( CH2 ) 3 --r~ NH-S02 ;~ C~ NJ~NH ~NH-COcH3 3/ ~N-N4 CF3 Cl ,` .
.' ,:

. . . . .... . .. . . . .. . . ... . . . .

)6 ~ O NH CH (CH3)2 .. '~,'' ~ ,.
8 r ~S02-- HO3S o NH ~ ~ N ~N

~''' ' \~ "-:'. ' . ~ ' . , ~
.~ j , . , .
. :::
~ 9. N33C16 ~ C-CH-NH-502 ~ NH-COcH3 ~ ;
, ` .: : / \

~ ~ N_N ~

~:;
Cl H-S02 ~ N=N.
~r;~ 10~ H35C17~ N ~N
N ~~,~' OCH3 H

` NN-SO ~ N~-CO-CN
H35C17 ~ ' 2 ~ 3 N OH ~ H

CO =N ~
[ ~ 3 Cl .

: ' .~A-G 1315 - 13 -. - , , " , . ...
, . ; , , :

~ 1~76~6 H a NH-S02~ N~I CO-C~I3 12. 3517 rIO >~<

:~ I o ~ 4~ :

., W Cl .'' ..
, ~'' ,~ ;, S02-~ ~NH-CO-CH3 `)~ NH CO-NH~OH ~OH
CO Cl~Cl ll=N~ ~ :

-tert ~ Cl Cl yl . :
C5Hll-tert.

",~ ~: ; . , : : ' i, . : : ::
. : ~ "' `

, . :.: .

NH-SO2~ NH--CO-CH3 ~ ~ :
14 . H35C17 I J( ~<
. ~ N NH2 ~ /~ OH ` ~
Cl I C1 ~ /--\ . :
~1/ \ N=N-( ) Cl `~ Cl : . ' ' ` , .'' " ` ' .
, ':,- ' ` .' ,, ` ;, , , ,` :," : : ,;, '" , ;;, 5- ~l7H3s ~ ~-- S~z~ r ~ :

^ ,,~ .
...
,l ~ A O

16. 1 5 ~H-S02~ 3 OH ~ OH

tert.-HllC5 N=N4~

Cl ~ ~:

x, ~

3 ~ 17, ~ OC
H3 ~' OC16H33 ~--C l .` , : ' ~ ~: A-G 1315 . - 15 - ~
.
~,~ ' . ' `. ~,. ' . .
:'`

. '.
~, , ;' ' . .
: , , , ,. .", ~ . ~
- , . :
.. ,- . . . ., : , ~:
, .,, . . . ' ' ' ' , ' ' ' :
1~76~

18, ~NH-S02- ~ ~ 3 rCH2j1 5 CH3 N=N-~: ' ' ' ; ~ - ~N=N-~3 SO - ~-NH-COCH
19. ~ 2~ 3 H ~ ``; :
~S02-LC-H2¦1 1-CH3 ' ~ ' -: ~N=N-Cl~-~NH-COCU~

O-~CH2~?1 5CH3 ~ :

. ., ~ ~ . .

21. SjC NS-502-~-OH C~
~ ~ ~ ~rJ -NH-COCH3 l : ~
H \~
~L o-LcH2~715-cH3 .. . .
~ . ~

'` ~ A-G 1315 - 16 -~, ',~ . . .
".' ~ . ' ' :

, ! , ''''" '` '' ., ~ .
' ' ' , ~

; ~ . ' ' , . . " , . . . , , ' ' ' ~ .' ' ' ' ` ` ' ,` ' ' . ., ~ ' . '' . ' . ' ' ~`. ` 1~)7~ 6 ``'`

~N=N- ~

22~ ~ NH-SO2- ~ -NH-COCH3 N ~ S02-NH-~CH~ CH3 " : `
:, ', , - `
N=N-~

C~ -N~OG~

S2-L~H2~ CH3 N=N- 4~
<~OH CI' :
24. Cl ~lH-so2- ~ -NH-cocH3 -~ H271~-CH3 =N-25. ~ ~ -NH COCH3 o~!H271 1 -cH3 ': .
`,. ~: ~: ~ ' . ` :
`~ 'i ' ' ' .`, ::
`, ~' ~ ` , .,`~ . . ' ' ... , .
. A-G 1315 - 17 -.. ~ ' " '' `

, ........................................................................ j - , "': ' ' ' ' ' ' `' 761[)6 26, ~ -OH ~

. Cl ~ NH-SO2- -NH-COCH3 ~,S02-NH-~H ~11-CH3 H

. ~ ' - .
N=N~ Q
. ~ -OH
:. 27. CH3 NH-SO2- ~ -NH-COCH3 N ~ So2-NH-~cH2711-cH3 H ~

r ~
.~1, ~ . . .
NH-SO - N = N- 3 28. ~ 2 ~ ~
~: ~ N ~ ~3 ~ ' :

S2- ~H2711 CH3 , ' . ~ ' . ':
: :
. "
. ~ NH- ~ -NH-CH(C~3)2 . NH-SO2 ~ o= A =o CH~

So2-LcH2711-CH3 ' . ~: , ' ' ' :................................ - . .
.... .

: , , ' `'~ , ' ' . ' ' ""~

`'' ' ' ' . ' . :

. ~: . .. . . - . . . ..
: . . . . ~ : . . .. ..

61()6 , : ~ N=N-:- ~ OH \;=~ :~

NH-SO2- ~ -NH-COCH3 :` H ~
~ L 2-711 3 .
. ,:' ` , N=N-."3 ~1 Cl NH SO2-~ ~-NH-COCH

bl~ ~H ~
~ ~ : : o-LCH271 1-CH3 ::
, y~
. :! .
.,Ç`i ~_~,N=N-' `~ ~ -OH
32T H3C ~ ~ -NH-COCH3 S ~ H~ CH

.~ N=N--OH
33. H3C ~ NH-502- ~ -N~-COCH3 ~ H ~
`. SO2-~CH2711-CH3 ~ `; . , .
~,'' ` , .

i~; , .
`~- A-G 1315 - 19 -.`' ' , , ' , .
'''' ' ' .

~ . . .

...
`:
.

, ~76~06 `- N-N~
OH Cl .

34. Cl ~ 1 92- ~ -NH-COCH3 ;. . S rCH~11 3 . , .
. N=N- ~

., ~ : :' 35- H03S ~ NH-S02- ~ -NH-COCH3 '1` N ~ ~.

o-/CH~71 5-CH3 - . , , .
.
NH-S02~ ,-NH-COCH3 36. OH3- [H2715-NH 02S ~ 3 ;-OH

H C~
. , -, ~ ~:`:
` NH-SO2- ~ -NH-COCH
37- CH3-~CH2715-NH-so ~; ~ H C(cH3)3 =N-~: -~ ~ Cl .;:
.. ; ~ ' . ' ' 3S- ~ C-~H2715-NH-SD2 ~ 2- ~ -N~ COCU~

-. A-G 1315 - 20 -, ' :' , .: ' , ~, ~ . , , ' , ' . , . ', ' , , , ' , . ,, ~ , ' , , , , . , 1 . , .

:1076~6

4.9 g of compound (I), whose production is described :`:` hereinafter, were 3uspended in 50 ml of pyridine, followed ~-~ by the addition of 4.3 g of the dye sulphochloride:
;'` '' ' . ' Cl~3C ~ =N- ~

.: ~
S02Cl ,, ~he solutlon was heated to 45C and then left to cool.
~ Following the addition of 50 ml of water, the solution was - stirred for l hour. The precipitate was filtered of~ under ~ sUction and washed with water~ The residue was suspended ,, .
in acetone, filtered under suction~ washed with acetone : 1~ and dried.
Yleld; 5.2 g of compound 2.
" ~
.... Compound (I) corresponding to the formula:
,i. l, ~ :
H35CI7 ~NH2 ;1: ~ ~ NH
"~ - ~ (I) .-' ~ 1 11 :". :.1 . ~ S03H .~
. ~ , .
:. , .
. . was obtained aa follows:
. 20.7 g of the pyrazolobenzimidazole corresponding - 15 to the formula:

A-G 1~15 - 21 -... .

~: .

.

, ` . , .
: . ' . ... - .. ~ ,, .,. , ' .

10761~
. . ~. .

N~ N
I `N
. ~ ' '' -: ~ ~J
,: ~ :.
. S0 were suspended in 150 ml of glacial acetic acid9 followed by the dropwise addition at room temperature of a solution of 3 3 g of NaN02 in 12 ml of water. The suspension was then stirred for 2 hours and subsequently introduced into ; ~ 5 a solution of 22.6 g of Na-dithionite in 150 ml of water, followed by stirring for 30 minutes After filtration under suctio~ the product was washed with water. The residue was suspended in 250 ml of methanol, followed by the addition of 250 ml of water. The product was then heated to boiling point, cooled~ filtered under suction~
; ~ .
washed with methanol and dried under nitrogen.

Yield: 18.2 g Compounds l and 3 are obtained in the same way as compound 2 by reacting compound (I) with the dye sulphochlorides . . . .
7'~ 15 corresponding to the formulae:
CH3-NH-C0 ~ N _ N ~ o2Cl N 0~ ~ and ( CH3 ) 2 ~ S02Cl H03S 0N~ ~
'' >=J' ' ' :
~ A-G 1315 OC~3 ~ 22 -, : .
~.

,; , . . . ,, . , . -. , . ,. , . . , . .. .. . . ~. ... .,, . . ~. :: . . : .

1~6106 ~ . ,...... .

4.4 g of compound (II), whose production is described hereinafter, were suspended in 50 ml of pyridine, , . . .
followed by the addition of 4,3 g of the dye sulphochloride used for the production of compound 2. The mixture , was heated to 40VC until a solution was formed, stirred for 15 minutes at 40C, and then cooledO 50 ml of water -~ were added dropwise, and the precipitate was filtered off ;;l under suction and washed with water. The residue was !
suspended in acetone, filtered under suction, washed -with a little acetone and dried.
Yield: 5 g of compound 4.
~` Compound (II) corresponding to the formula:
... . .
I5 H C ~ NH2 N ~ (II) o~3 was obtained as follows:
6.2 g of compound (III) (for production see below) were . , .
suspended in 170 ml of glaoial acetic aoid, followed by the addition in portions of 9 g of zinc dust. The whole wa~ stirred for l hour at room temperature and then for 30 minutes at 40C, filtered under suction and w&shed with .. . .
glacial acetic acid. The mother liquor was concentrated in vacuo and the greasy residue was stirred with 50 ml of ~; methanol, filtered under suction, washed with methanol and dried under nitrogen.
Yield: 5 g of compound (II).

' . , ' ~ ' . 1 .

., " .
~ ~76iL06 .,. . ,~
: ~ Compound (III) corresponding to the formula:
: ~; ...

NO
. ~ ~' H~5C1 7~ :~
~` ~ NH (III) o6~
"' ' ' ' :
was prepared as follows:

9 g of the pyrazoloquinazolone: :~
:, :

H35C17_ were suspended in 75 ml of glacial acet;lo acid, a~ter

5 ~ whloh l.65 g of NaN02 were added and the mixture ~tirred ~ :
for 4 hours with a positive nitrite reaction. After s ~ ~tanding overnight, the product was filtered off under suction, washed with H20 and dried.
Yield: 7.7 g of compound (III).
:10: _ ~
. ~ ~ 4.9 g of the dye sulphochloride used ~or the ,., ~ :
: produotion oi compound 2 were brlefly boiled with . stirring in 70 ml of anhydrous chloroform and 3.55 ml of anhydrous pyridine, followed by the addition of 5.0 g ~ 15 of 4-hexade¢ylo~y-~-aminoacetophenone h~drochloride~
; After boiling for a further two hours, the produot was cooled.
. After undissolved components had been flltered off under suction, the solution was stirred twice with lO g of , : A-G 1315 - 24 -'~, i . ,:' , ', , -:
~.' ' ' i ' ; ` 1~76~6~
~ .
Kieselgel G, a product of the Merck Company~ Darmstadt, and then filtered under suction. The silica gel residues ....
were extracted with a little CC14. The combined C~Cl3 and ~ CCl4 solutions were concentrated by evaporation in vacuo, -~ 5 and the residue was stirred with a little petroleum ether, filtered under suction and dried. Yield:`1.7 g oi compound 9.
4-hexadecyloxy~ -aminoacetophenone hydrochloride was obtained as follows:
~ 72 g oi 4-hexadecyloxy acetophenone were dissolved in ; lO 350 ml of glacial acetic acid at 50C 32 g of bromine were added dropwise with stirring in such a way that the internal temperature remained at 50C in the absence of heating. On ~:
continued stirring in the absence of heat, a depo~it was precipitated. The deposit was filtered off under suction at room temperature, washed with water, dried in ~acuo over KOH
and dissolved in 250 ml of chloroform. The solution was freed from residual water with Na2S04 sicc. and filtered9 ;;;~ followed by the addition of 28 g of hexamethylene tetramine~
~, :i . , , After standing overnight, the hexamethylene tetramine hydrobromide precipitated was filtered off under suction ~` and substantially twice the volume o~ ethyl aoetate was added ~;~ to the filtrate. The precipitate was filtered o~ under ~uction, washed with ethyl a¢etate and dried~ Yield: 51 g.
The product thus obtained was dissolved un~er heat in . . , ~` 25 840 ml of ethyl glycol, followed by the addition at room temperature of 24.6 ml of concentrated hydrochloric acid.
Aiter a few hours~ ~tirring at room temperatu~e~ complete di~olution occurred~ followed by the gradual precipitation oi a solid produ¢t. After ~tanding overnight, the product ~as filtered under ~uction and dried. Yield: 34.2 g.
Further material, if any, may be precipitated fram the mother liquor with acetonitrile.
A-G 1~15 - 25 -. '. '.
.'' , .
:. ' . !

. ~ , .

: : :
76~06 , It is of course possible to apply other methods which lead to the compounds according to the invention. For example, suitable compounds may be coupled with diazonium salts, reduced by known methods to ~orm ths corresponding enolamines or endiamines or their tautomers and reacted with dye sulphochlorides to form the compounds according to the invention.
The dye-giving compounds according to the invention are incorporated by any of the usual methods in casting solutions for the layers of the photographic material.
The ~uantity of dye-giving compound used per litre of casting , solution varies within relatively wide limits, the most ; favourable concentration being determined by simple tests. For example, from 5 to 80 g and preferably ~rom 20 to 40 g of the dye-giving compound are used per litre of the solution.
The association between the non-diffusible dye-giving compound and silver halide which is necessary for obtaining ;`~ the required effect may be obtained, for example, by introducing the non-diffusible compounds into the casting solutions from aqueous-alkaline solution~ utilising the .: , water-solubilising groups present. However, the non-diffusible ~ .
- dye-giving compounds may also bs introduced into the layers by any of the ~nown emulsification processes. Processes il`; 2S o~ this kind are described, for example, in British Patent ;- Specifications Nos. 791,219 and 1,099,414 to 1l099,417. It is also possible to prepare aqueous dispersions of the dye-giving compounds and to add them to the particular casting sol~ions.
To this end, aqueous suspen~ions of the dye-gi~ing compound are finely ground, for example by ln~e~3~ve stirring in the presence o~ sharp-edged sand or by applying ultrasonios.
In another embodiment, it may be desirable for example to , ' ,, '' .
. '; ,, .

, , . - ;. , , : , ~

` 1~76106 : ` " ,~
~ incorporate the dye-giving compounds together with silver -~ halide and, optionally, developer substances in the layer in the form o~ so-called micro capsules, in w~ich case two or more differently sensitised photo~ensitive silver 5 halide emulsions and the corresponding non-diffusible compounds may be combined in a single layer in the manner . ~ .
; of so-called mixed-grain emulsions 9 as described for example in American Patent $pecification No. 2,698,794. The non-diffusible dye-giving compounds may be accommodated in 10 a photosensitive layer itsel~ or in an adjoining layer.
For example, a compound releasing a blue-green dye is .
~i associated with the red-sensitive layer, a compound ;~ releasing a magenta dye is associated with the green-~, sensitive layer and a compound releasing a yellow dye is associated with the blue-sensitive layer .
In the context o~ the invention, "association" and ~(; "associated" mean that the mutu~l arrangement of silver halide -~ emulsion and dye~giving compound is such that they may interact to allow imagewise consistency betwee~ the -~` 20 silver image ~ormed and the imagewise distribution of the diffusible dye liberated. The associated dye~giving compound ~`~ is best incorporated in the silver halide emulsion itsel~
`- or in a layer adjacent to the silver halide emulsion layer, this adjacent layer pre~erably lying behind the silver - 25 halide emulsion layer (as seen in the direction of the incident light during exposure).
The dye-giving compounds according to ~he invention are oxidised imagewise by developer oxidation products during development of the silver image and, under the . .
influence of the developer or activator alkali, subsequently undergo a splitting reaction in which the dye radicals are ;
liberated in diffusible form as dye sulphonamides.The usual .
' ' : ' ." , ' '. ,. - . ' . ' , ~
,.', ' ' ', ' '',~ ' ' ' - ~' ' .

` ;
~(176~
- photographic developer compounds may be used for development providing they are able in oxidised form to oxidise the c dye-givingCmPounds according to the invention. The ~` following are examples of suitable developers: -, "
hydroquinone , N-methyl aminophenol ; l-phenyl-3-pyrazolidone ~
l-phenyl-4,4-dimethyl-3-pyrazolidone aminophenols N,N-diethyl-P-phenylene diamine ~- N-ethyl-N-hydroxyethyl-p-phenylene diamine 3-methyl-N,N-dlethyl-p-phenylene dlamine N~N,N'N~-tetraalkyl-p-phenylene diamines, such as tetramethyl-P-phenylene diamine, triethyl sulphobutyl-P
15 ~ phenylene diamine and l,4-bis-pyrrolidinobenzene~ and reductones It is expressly pointed out that the choice o~
developer substances in the proces~ accordlng to the invention is not confined to colour developers. Instead oonventional black-and-white developers may also be used, which may be regarded as an advantage by virtue of the lesser tendency of black-and-white developers towards discoloration. The developers may ~ctually be present in the layers oi the colour photographic material where ; 25 they are aotivated by the alkaline activator liquid, or in the alkaline processlng liquid or paste. Since the dye-givingcompounds according to the invention " :
~ them~elves have developer properties, there is no need - : .
in individual cases to use auxiliary developer compounds.
In cases such as these, thedye-giving compound iB directly oxidised by developable silver halide.
Since the imagewise distribution oi' the dl~iusible dye . ' I
. ' .

... . . . . . . . . . .
- :,, : , ,, . , ~ : , ~ , ;:, , ~ 1~761~)6 ~ release~ during development is consistent with the developed , .
- silver image, it is necessary, in order to produce positive - coloured transfer images, to use direct-positive silver halide emulsions or, in cases where conventional negative emulsions are used~ to apply a suitable reversal process.
A reversal process of this kin~ is available in the silver salt diffusion process. Photographic reversal by means of the silver salt diffusion process for producing positive coloured images using conventional colour couplers is described, for example, in US-PS 2,763,800. Replacement of the colour couplers by the above-mentioned dye-giving compounds gives a photosensitive element which is suitable for the dye di$fusion transfer process. A photosensitive element of this kind comprises, for example, at least -one combination of a photosensitive silver halide emulsion ` layer and, associated therewith, a binder layer containing development nuclei for the physical development process and a dye-giving compound.
During development, the exposed part of the silver halide is chemically developed in the photosensitive silver halide emulsion layerO The unexposed part is transferred by means of a silver halide solvent to the associated ~;~ binder layer containlng development nuclei where it is physically developed. In cases where physioal development is carried out with a developer which, in oxidised form, .~ i8 able to release a dlfi~usible dye a~ a result of a reaction with the dye-giving compound present in-this layer, diffusible dyes are distributed imagewise and may be transferred to an imgae-receiving layer where they form a positive coloured image.
In cases where reversal is carried out with compounds which release development inhibitors in imagewise arrangement, , . .

''' ' .

.
.: I
.
,-.: .. . . . .. : . . :
..

., ' , ., .,. ' ' . ' . . ., ;' .

1(~761~6 the photosensitive element consists of at least one layer combination of a photosensitive silver haIide emulsion layer and a second emulsion layer which can be developed without exposure and which contains the dye-giving compound. The ~`~ 5 photosensitive silver halide emulsion layer is developed for example with colour developers in the presence of certain compounds which release development-inhibiting substances during the reaction with oxidised colour ~ developer. The development-inhibiting substances released ,~ lO imagewise in the photosensitive layer diffuse into the .:, ~l adjacent emulsion layer developable without exposure where , they inhibit development in an imagewise distribution. The non-inhibited (positive) parts of the emulsion Iayer ;~ developable without exposure are developed by the residual .,, ~, . .
developer whose oxidation products subsequently react with ~`` the non-diffusible dye-giv ~ compounds according to the ~`~ invention to release diffusible dyes which are transferred imagewise to the image-receiving element. Suitable compounds .....
~ ~ which release development-inhibiting substances on reaction .
with colour developer o~idation products are, for example, -~
the known DIR couplers (DIR = development inhibitor releasing), which are colour couplers containing a releasable inhibitor radical in the coupling position. DIR couplers o~ this kind are described, for example, in US-PS 3,227,554.
; 25 Another group of compounds which release development-inhibiting substances on reaction with colour devcloper oxidation products is described in US-PS 3,632,345. These compounds are not colour couplers. Accordingly, no dyes are formed on the release of the development-inhibiting - substances. Finally, according to ~ l,P2~ 89~ it is ,, .
also poqsible in a process of this kind to use suitable substituted non-dii~usible hydroquinone compounds which are A-G 1315 ~ 3 ~
.. ~ .
.
. . .
. ,, , .- - . ~ . . . .
, : , . , , . : , ~07610~;
: .
oxidised into the corregponding quinones on reaction with developer oxidation products, releasing development-inhibiting mercaptans, In principle, suitable direct-positive silver halide .
emulsions are any direct-positive silver halide emulsions which need only be developed once to produce a positive silver image and an imagewise distribution of developer oxidation products corresponding to this positive silver ; image. For example, it i9 possible to use silver halide emulsions in which exposure to light or chemical treatment ; has resulted in the formation of A developable fog which is destroyed imagewise during imagewise exposure under certain conditions. The ~og remains intact at the unexposed areas, so that a direct-positive silver image is obtained during subsequent development and~ in consistency , ~ .
therewith, an imagewise distribution of diffusible dye is formed when a dye-giv~compound according to the invention is associated with the direct-positive silver halide emulsion.
Another group of direct-positive silver halide emulsions ~ ~ 20 which may be used in accordance with the invention comprises `~ thè so-called unfogged direct-positive silver halide emulsions .~ ~
which are photosensitive predominantly inside the silver halide grains. When emulsions of this kind are exposed ~ imagewise~ a latent image is formed predominantly inside -~ 25 the silver halide grains. However, the development of unfogged direct-positive silver halide emulsions of this ; kind is carried out under fogging conditions where a fog is produced predominantly at the unexposed areas and a ~ ,; ~ .-.
positive silver image i3 developed during development, ~0 The unfogged direct-positive silver halide emulsions are ` characterised by the fact that, when developed with a ; typical surface developer of the following composition:
~; A-G 1315 - 31 -~ .
'' ~ .
,'~' ', ':

)6 - ..
,,. , p-hydroxy phenyl glycine lOg sodium carbonate (crystallised) lOOg made up with water to lOOOml exposed samples preferably form no silver image, or only a silver image of very low density, whereas in cases where an internal developer of the following composition:
hydroquinone 15g monomethyl-p-aminophenolsulphate 15g sodium sulphite (anhydrous) 50g . 10 potassium bromide lOg ~`; sodium hydroxide 25g sodium thiosulphate(crystallised) - 20g ; made up with water to lOOOml is used, a silver image of adequate density is formed. ~:
Selective ~ogging of the unfogged direct-positive emulsions which have been exposed imagewise may be carried ~ out before or during development by treatment with a ; fogging agent. Suitable fogging agents are reducing agents, such as hydrazine or substituted hydrazines In this connection, reference is made, for example to US-PS
3,227,552.
. . , Unfogged direct~positive emulsions are, for example those which show fault~ inside the silver halide grains (US 2~592,250), or silver halide emulsions with a layered grain ~tructure ( ~ 2,308,239).
The emulsion~ may also be chemically sensitised, ~or example by the addition during chemical ripening of sulphur-.~
~- containing compounds, i~or example allyl isothiocyanate, allyl thiourea, sodium thiosulphate and the like. Other suitable chemical sensitisers are reducing agents, ior example the tin compounds described in Belgian Patent Specl~ioations Nos 4g3,464 and 568,687, and polyamines such A-G 1~15 - 32 -.; .
,'," ,. .
.~ ' , .

1~7~

as diethylene triamine or a ~ /méthane sulphinic acid -~ derivatives, for example according to Belgian Paten$
Specification No. 547,323.
Other suitable chemical sensitisers are noble metals and noble metal compounds, such as gold, platinum7 palladium, iridium, ruthenium or rhodium. This method of chemical sensitisation is described in the Article by R. Koslowsky, in Z. Wiss Phot. 46, 65-72 (1951).
The emulsions may also be sensitised with polyalkylene oxide derivatives, for example with polyethylene oxide with : .
a molecular weight of from 1000 to 20,000, and with condensation products of alkylene oxides and aliphatic ` alcohols, glycols, cyclic dehydration products of hexitols,w1th alkyl-substituted phenols, aliphatic carboxylic acids, aliphatic amines and aliphatic diamines. The condensation . ~, , ; ; products have a molecular weight of at least 700, preferably :; 2 - more than 1000. In order to obtain special effects, it is `' of course po~slble to use these sensitisers in combination with one another, as described in Belgian Patent Specification No. 537,278 and in British Patent Specification No. 727,982.
The emulsions may also be spectrally sensitised, for ~ exacple by the usual monomethine or polymethine dyes, such ;~ as acid or basic cyanines, hemicyanines, streptocyanines, .. ' :
merocyanines, oxonols, hémioxonols, styryl dyes or other 25 even trinuclear or polynuclear methine dyes, for example ; ~ rhodacyanines or neocyanines. Sensitisers of this kind are described, for example in F.M. Hamer~s book ~The Cyanine Dye~ and Related Compounds~' (1964), Interscience Publishers, John Wiley and Sons. -The emulsion5 may contain the usual stabilisers such as, for example, homeopolar or salt-like compounds of mercury with aromatic or heterocyclic rings, such as ~, , .
' ,:

. , ' ,':

- ;- 1076~
,, ~
; mercaptotriazoles, single mercury salts, sulphoniu~-mercury double salts and other mercury compounds. Other suitable stabilisers are azaindenes, preferably tetra- or penta-azaindenes, more especially those substituted by hydroxyl or amino groups. Compounds of this kind are described in the Article by Birr in Z. Wiss~ Phot. 47, 2-27 (1952).
. , .
Other suitable stabilisers are inter aiia heterocyclic mercapto compoundsj for example phenyl mercaptotetrazole, , . . .
: quaternary benzthiazole derivatives, benztriazole and the like.
Gelatin is preferably used as the binder ~or the photographic layers. However, it may be completely or partly replaced by ... .
other natural or synthetic binders. Examples of natural binders are alginic acid and its derivatives, such as its ;
salts, esters or amides, cellulose derivatives, such as carboxy methyl cellulose, alkyl cellulose, such as hydroxy ~; ethyl cellulose, and starch or its derivatives, such as ethers or esters or caragenates. Examples of synthetic binders are polyvinyl alcohol, partially hydrolysed polyvinyl acetate, polyvinyl pyrrolidone and the like.
The layers may be hardened in the usual way, fbr example with formaldehyde or halogen-substituted aldehydes containing a carboxyl group, such as mucobromic acid, diketones~ methane ~: ,i 1 ~ ~ sulphonic acid esters or dialdehydes. Also other hardeners m~y . . .
I be used as for example fast acting hardeners such as carbodi-` 25 imide hardeners) carbamoyl pyridinium salts and carbamoyloxy-pyridinium salts. Referenoe is made in this respect to German Offenlegungsschriften 2,263~602; 2,225,230 and 1~808,685.
The dye diffusion transfer process according to the invention is carried out with a photosensitive element containing one or more silver halide emulsion layers and the non-di$fusible dye-givingcompounds a~sociated therewith, and with an image-reoeiving element in which the required , .
dye image is produced by the diifusible dyes trans~erred A-G 1315 - 34 ~

.

~L0761~6 . ~
imagewise. To this end, the photosensitive element and the image-receiving element must be in ~irm contact with - one another for at least a finite period during the development time, so that the imagewise distribution of di~fusible dyes, produced in the photosensitive element in consequence of development, can be transferred to the image-receiving element. Contact may be established after development has started. Alternatively, it may even be established be~ore the beginning of development. This is the case, for example, where the dye diffusion transfer process is carried out with a material in which the photosensitive element and the image-receiving element form an integral unit, hereinafter also referred to as one-sheet material, which remains intact even after development is over. In other words, the photosensitive element is not separated from the image-receiving element, even after dye transfer. An embodiment of this kind is described, for example in DT-OS 2,019,430.

.... . . .
~ A one-sheet material ~uitable for carrying out the .` ~ b 20 dye diffusion transfer process according to the invention comprises, for example, the following layer elements:
l) a transparent layer substrate ' -i 2) an image-receiving layer -~ 3) a light-impermeable layer 43 a photosensitive element with at least one photosensitive silver halide emulsion layer and at least one non-dif~usible dye-giving compound associated therewith 5) a retarding layer -~ 30 6) an acid polymer layer . 7) a transparent layer substrate The one-sheet material may be assembled by separately :~
A-G 1315 - 35 ~

, :

- 1076~ ~6 producing two di~ferent parts, namely the photosensitive part (layer elements l to 4) and the cover sheet (layer .;
- elements 5 to 7) which are then placed layerwise on one another and joined together, optionally using ~pacer strips, so that a space large enough to accommodate a measured .
quantity o~ a working liquid is formed between the $wo parts. ~he layer elements 5 and 6, which together form the neutralisation system, may also be arranged, although with ;~ the sequence reversed, between the layer substrate and the image-receiving layer o~ the photosensitive part.
Means may be provided ~or introducing a working ; liquid between the photosensitive part and the cover sheet, `
~or example in the form of a laterally arranged splittable container which~ under the action o~ mechanical forces~
releases its contents between two adjacent layers oi the ` one-sheet material.
An important part of the photographic material according to the invention is the photosen~itive element which, in the case of a one-dye trans~er process, contains ~ 20 a photosensitive silver halide emulsion layer and, nssociated -~ therewith, a non-dif~usible dye-giving compound. The non-dlffusing compound may be ~ituated in a layer adjacent to the .: .
silver halide emul~ion layer, or in the silver halide emulsion layer itself, in which ca~e the colour of the image dye is preferably selected in such a way that the predominant absorption range oi the dye-giving compound is not consistent with the predominant sensitivity range oi the ~ilver halide emul~ion layer. However, in order . .-, .
~; to produce ~ulticoloured transfer images in natural colours, the photo~ensitive element contains three ~uch associations of dye-givingcompound and photo~en~itive ~ilver halide emulsion layer, in which case thé absorption range oi , ' . .
'' ' ' '76~06 ; the colouring compound i8 generally substantially consistent with the spectral sensitivity range of the associated silver halide emulsion layer. In this case, however, the colouring combination must be arranged in a separate binder layer behind the silver halide emulsion layer (as seen in the direction of the incident light during exposure) to ; ensure maximum sensitivity.
The developer oxidation products formed during the development of a silver halide emulsion should of course 1o only act on the associated dye-gi~ing compound. Accord m glY~
the photosensitive element generally contains separation ~ layers whlch effectively prevent the developer oxidation - product~ from diffusing into other non-associated layers.
These separation layers may for example contain suitable substances which react with the developer oxidation products, for example non-diffusible hydroquinone derivatives, or .i if the developer is a colour developer, non-diffusible ; colour couplers. In one preferred embodiment, therefore, the photosensitive element has the following struoture ~ ~ 20 (going downwards~:

`, ,t` ~ ~ blue-sensitive silver halide emulsion layer, layer containing a non-diffusible compound releasing ``~ a diffusible yellow dye separation layer green-~ensitised silver halide emulsion layer .;. ~
; ~ layer containing a non-diffu~ible compound whioh ~ releases a diffusible purple dye - separation layer red-sensitised silver halide emulsion layer layer containing a non-diffusible compound releasing a diffusible blue-green dye.
The silver halide emulsion layers ma~ of oourse also .
be arranged in a different order~ although in this ca~e the as~ociated layers containing the colouring systems must A-G 1315 ~ 37 ~
. .

:: ,, , - , "

76~06 ., .,_. .
also be changed around so that the association remains intact The light-impermeable layer arranged below the photosensitive element is permeable to aqueous alkaline treatment solutions and, hence, to the diffusible dyes It has essentially two functions. Firstly, it is used to mask the image silver left after development in the originally photosensitive element, and the dye-giving compounds left behind as colour negative, so that it is only the positive dye transfer image which is visible . ~ ' 10 through the transparent layer substrate of the photo-sensitive part. Secondly, it seals off the photosensitive ~` element on the side of the image-receiving layer (downwards) ~- in light~ghtmanner. This is of particular significance t~, ~
in cases where, after exposure, the one-sheet material is intended to be brought into contact with the alkaline ,. .
processing mass in the camera~itself, subsequently removed from the camera and developed outside the camera Layers with adequate impermeability to light but with adequate permeability to diffusible dyes may be prepared 20 for example with suspensions of inorganlc or organic dark-coloured, preferably blaok pigments, for ex~mple with ; suspensions of carbon black in suitable binders, for -- example in gelatin solutions. In general, layers which are 0.5 . , . . ~ .
` to 2 y thick and which contain from lO to 90~ by weight (based ~.:
~` 25 on the total dry weight) oi carbon black in gelatin are ,:'.'~:
generally su~ficient for guaranteeing the exclusion of light during development to an adequate extent The ~`S particle size of the pigments used is relatively non-critical providing it does not appreciably exoeed 0.5 p.
~, 30 In addition to the black pigment layer~ the light-impermeable layer preierably comprises a white pigment layer ~: arranged below the black pigment layer. The iunction of this white pigment layer is to cover the black layer and to provide a white background ior the image. Any white A-G 1315 ~ 38 -,-;
", . :" -... ,.. .-, --,, , ., - ,. , .

761~6 . . .
pigments may be used for this purpose providi~g they have an adequate covering power in not excessive layer thicknesses, ~xamples of suitable white pigments are barium sulphate, oxides of zinc~ titanium, silicon, 5 aluminium and zirconium, and also barium stearate or kaolin.
Titanium dioxide is preferably used as the white pigment. The white pigment used has to satisfy the same requirements as the black pigments in regard to binder, concentration and particle size, The thickness 10 of the white pigment layer may be varied according to the ;~ required whiteness of the background. The white pigment is ; preferably used in la~er thicknesses of from 5 to 20 ~.
Instead of the light-impermeable layer, it is also possible in aocordance with the invention to arrange in .. ~. ~ .
15 the one-sheet material means for producing a light-impermeable layer of this kind between the photosensitive element and the image-receiving layer, for exampl`e in the form of a laterally arranged container with a working liquid containing a clouding ~ agent (pigmentj which, under the effect of mechanical forcesf i~ 20 releases its contents between the above-mentioned layers so -~
' that a pigment layer of the kind in question is formed `~ 1 :
~;~ between them.
-~ The image-receiving layer consists essentially of a binder containing dye mordants for fixing the dif~usible dyes.
. ~
~ ` Preferred mordants for acid dyes are long-chain ~ . ...
; quaternary ammonium or phosphonium compounds or ternary sulphonium compounds~ ~or example those described in US Patent Specifications Nos. 3~271~147 and 3~271,148. It is also possible to use certain metal salts and their hydroxides whlch ~orm substantially insoluble compounds with the acid dyes. The dye mordant~ are dispersed in " ' ' ,. :
' , , , ' ' ' , `' :, . . . .. , , . ~ : :

76 lL~6 ~ .
~; the receiving layer in one of the usual hydrophilic binders, for example in gelatin, polyvinyl pyrrolidone completely , ~ .
or partially hydrolysed cellulose esters and the like.
Some binders may of course also function as mordants, for example copolymers or polymer mixtures of vinyl alcohol and N-vinyl pyrrolidone, of the type described for example in German Patent 1,130,284, and also polymers of nitrogen-containing quaternary bases, for example polymers . I .
of N-methyl-2-vinyl pyridine, of the type described for example in United States Patent Specification No. 2,484,430.
Other suitable mordanting binders are, for example, guanyl ~-hydrazone derivatives of acyl styrene polymers, of the type described for example in German OLS 2,009,498. In general, however, other binders, for example gelatin, ~ill generally be added to the last of the above-mentioned binders.
.,;~, ~ : .
~ Suitable transparant layer substrates for the one- ~ ~
.. . .
t~`~ sheet material according to the invention are any o the `;~ transparent substrates commonly used in photography, for example films of cellulosc esters, polyethylene terephthalate, polycarbonate or othar ilm-forming polymers. -~
A relatively high pH-valua ~approximately 11 to 14) is adjusted by the alkaline processing mass in the ; photosensitive material, thus initiating development and imagewise dye diffusion. It has been found that '': ,1 ':
the dyes and, hence, the images obtained are not particularly ~,` stable at this high p~-value. Accordingly, the material has to be made substantially neutral or weakly acid on completion of development. This can be done in known manner by providing the material with an additional, acid polymer layer which becomes accessible only gradually to the alkaline processing mass during - ~40-' -' " ' "' ' ' , ~ . ' . .
... . .

76~6 development In the context of the invention, an acid polymer layer is a binder layer containing polymerl¢
I compounds with acid groups, preferably sulpho or carboxyl groups. These acid groups reaot with the cations of the processing mass to form salts and, -;;
in doing so, reduce the p~-value of the mass. The ; polymeric compounds and, hence, the acid groups are ~ of course incorporated in non-diffusible form in the . . , above-mentioned layer. In many cases, the acid polymers are derivatives of cellulose or derivatives of polyvinyl ~ : .
` compounds, although it is also possible to use other : ,~
polymeric compounds. Examples of suitable acid polymers include cellulose derivatives with a free carboxyl group, for example cellulose dicarboxylic acid semiesters with a free carboxyl group, such as cellulose acetate hydrogen phthalate, cellulose~acetate hydrogen glutarate, ethyl .. , j ~. ..
cellulose acetate hydrogen succinate, cellulose acetate hydrogen succinate hydrogen phthalate, ethers and esters of -cellulose modified with further dicarboxylic acid anhydrides ~ ~
., ,. ~ :, 20 or with sulphonic acid anhydrides, for example with o-sulphobenzoic acid anhydride, carboxyl methyl cellulo~e, also polystyrene sulphonic acid, polyvinyl hydrogen phthalate, polyvinyl acetate hydrogen phthalate, poly-acrylic acid, acetals of polyvinyl alcohol with aldehydes 25 which are substituted by carbo~y or sulpho groups, such as o-, m- or p-benzaldehyde sulphonic acid or carboxylic acid, partially esterified ethylene/maleic acid anhydride copolymers, partially esterified methyl vinyl ether/maleic acid anhydride copolymers and the like.
~o The acid polymer layer must oontain a sufficient '! , . .
quantity of acid groups to reduce the pH-value of the proceasing mass from ita original level of ll to l4 to ~uch an extent that, finally, the material is either .`' ~ . , ,'.

7615)6 ~:
,~ .
substantially neutral or weakly acid ~pH-value 5 to 8).

'r; The delay in pH-reduction is obtained in known manner , .:
by coating the acid polymer layer with a so-called retarding layer. This retarding layer is an alkali-permeable layer which preferably consists of a polymer inert to alkali, for example polyvinyl alcohol or a partially acetalised `
polyvinyl alcohol. The delay in pH-reduction may be adjusted as required by suitably selecting the thickness and composition of this retarding layer. A re~arding layer e ; 10 containing polymers with novel permeability behaviour is described, for example, in German OLS 2,455,762.
;; Neutralisation systems, which are combinations of .~.................................................................... .. .
an acid polymer layer and a retarding layer, are described `

for example in German Patent 1,285,310. Layer combinations ~ of this kind may be present in the material according to the ~;

-~ invention, for example in the photosensitive part between - ;
.
s the transparent layer substrate and the image-receiving ,, layer. Another possibility is to arrange the neutralisation system of an acid polymer layer and a retarding layer on the cover sheet. These two layers must of course be arranged in such an order that the alkali in the processing mass has first to penetrate through the retarding layer in order to reach the acid polymer layer. ~ :
; The dye diffusion transfer process according to the invention may be carried out advantageou~ly in or by means of a suitable self-developer camera. This camera may be provided, for example, with devices by which it is possible, after exposure of the photosensitive element, -to distribute a working solution between the photosensitive element and the cover sheet, and to mask the photosensitive material in such a way that it is impermeable to light from ,:. :
-,,' j : 1~761,0f~
.
above. A camera of this kind is preferably provided with two squeezing rollers in contact with one another between :.:
which the one-sheet material is pulled out, thereby splitting open a laterally arranged container so that it releases its contents between the layers of the one-sheet material, , Since, after passing through the squeezing rollers, the photosensitlve element is protected on both sides against undesirable exposure by ~ght-impermeable layers, the exposed material may be pulled out o~ the camera immediately after the beginning of development, : For processing the one-sheet material after it has been exposed imagewise, the photosensitive element is brought into contact with the aqueous alkaline working solution. The silver halide emulsion layers exposed image-wise are developed in the presence of the developer compound, an imagewise distribution of oxidation products of the developer compound belng obtained in consistency with the positive silver image formed. These oxidati~n products oxidise the associated colouring compound which releases the diffusible dye by reacting with the alkali of the activator. The aqueous alkaline working solution may contain viscosity-increasing additives, for example hydroxy ethyl cellulose. The working solution may al90 contain in known manner development accelerators, stabilisers, silver salt solvents, fogging agents, ';
-~ antioxidants and other additives .. , .. "~','~ ' , ~'." , .
.
~ .; A-G 1315 43 -.-: , `' ' , ' , .. . . . .
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EXAMPLE 1 1 076~6 A photosensitive element of a photographic material according to the invention was prepared by successively applying the following layers to a transparent substrate of polyester film. The quantities indicated are each based on 1 square metre.
1) A mordant layer consisting of 3.6 g of octadecyl trimethyl ammonium methyl sulphate and 9.0 g of gelatin, ; 2) A re~lection layer of 48 g o~ TiO2 and 4.8 g of ge-.
latin, 3) A gelatin intermediate layer of 2.6 g of gelatin, 4) A dye layer with silver sulphide grains of 1.25 g.
of compound 1(yellow) and 3.35 g o~ gelatin, ~-~
5) A silver bromide emulsion layer having incorp~ratedthere-....~
in a black-and-white developer and consisting o~ 0.95 g of AgBrs 1.2 g of octadecyl h~droquinonesulphonic acid,0.36 g of octadeyl ~ hydroquinone ~nd ~ g o~ gelatin~ and ; ~ A protect~ve layer of 2.~ g of gelatin.
~ After exposure through a stepped wedge, the photo-. ~ .
~ - sensitive element was covered on the layer side with a poly--- ester gilm. A splittable container with an alkaline working :
liquid of the following composition was used for developing the imagewise exposed photosensitive eleme~t:
25 g of sodium hydroxide l g of phenidone 2 g of sodium thiosulphate ~, ~ , . .
4 g of sodium sulphite 1 g of parafo~maldehyde 10 ml of benzyl aloohol 30 g of Natrosol HHK 250 (hydroxy ethyl cellulose) ;~ made up with water to lO00 ml.
~he image set was guided through a pair of squeezing A-G 1~15 - 44 -:, .
. ~ . ...

.';. :
: ~ , '. ' ' , . . ..

0~61 [)6 ~I rollers so that the developer paste was distributed betwPen ~ ~J
the photosensitive element and the cover sheet. The paste -~I thickness was 140 u. In order to adjust the thickness of the paste~ spacer strips of corresponding thickness were . :i . .
arranged laterally along the edge of the image between the photosensitive element and the cover sheet. After an exposure time of 10 minutes at 20C, the image element was separated off and freed from the paste adhering to it. ;~
A positive yellow dye image of good colour quality was visible through the transparent substrate with the TiO2-layer as image background~

~:.1 ~ .. ,':. ,. :
' The procedure was repeated as described in Example 1, except that, instead of layers (4) and (5), the following layers --were applied:
4) A dye layer with silver sulphide grains of 0.83 g . , ~ .
of compound 2 (magenta) and 2.85 g of gelatin ~
. .: -5) A green~sensitised silver bormide emulsion layer of 0.67 g of AgBr~ 0.33 g of octadecyl hydroquinone sulphonic 1~
acid9 0.25 g of octadecyl hydroquinone and 1.5 g of gelatin. -~,:' :. -:
;` A positive magenta dye image was obtained after -`; ~ processing in the same way as ~n Example~l. Dmin 0.65;
: : .
Dmax 1.62.

; 25 The procedure was repeated as described in Example 1~ e~cept that~ instead of layers 4) and 5)~ the following layers were ~;
'.'! applied: ~ d . .
4) A dye layer with silver sulphide grains of 1.6 g of compound 3 (cyan) and 2.2 g of gelatin 30 5) A red-sensitised sllver bromide emulsion layer of 1.65 g of AgBr~ 1.2 g of octadecyl hydroquinone sulphonic acid~ 0.35 g of octadecyl hydroquinone and 2.0 g of gelatin.

' .

-45- ~

, :-` . . : ' :,, ',' . ", ` , ' ., '''. ~ ~ .', ,' '" ',, '. . ", ~ ''., ',.''., ,'''' ' ' ,'. ''.,, ;,.

~ A positive ~yan dye image of good colour quality ~
; was obtained after prooessing in the same way as in Example 1.
`~ EXAMPLE 4 The procedure was repeated as descrîbed in Example 2,except ~i 5 that compound 2 in layer 4 was replaced by compounds4, 5 and 9. Positive magen~a dye images were obtained in each case after processing in the same way as in Example 1.

The photosensitive material described in Example 2, was developed in the same way as in & ample 1, except that, lnstead of phenidone, the compounds identified below were used as auxiliary developers. They were each used in a .~
^ quantity of 5 g per litre of paste. ~he following results ~ ,~
`~ were obtained: ;
~ 15 ,~"~ ~ . . ,, Auxiliary developer Dmin Dmax ,. ~ __ -~
~ N-ethyl-N-hydroxy ethyl-p-; phenylene diamine 0.55 1.31 N-methyl aminophenol 0.45 1.67 Pyrocatechol 0.49 1.58 -` ~-tolyl hydroquinone 0.77 1.56 Piperidinohe~ose reductone ~ - monoaoetate 0.53 1.56 ;~ l-phenyl-4-methyl-4-hydroxy methyl-3-pyrazolldone 0.51 1.67 _______________ -~'. ' ~ EYANPLE 6 - The following layers were applied to the substrate ~ described in Example 1 (transpArent ~ubstrate, layers 1~ 2 . , .
and 3): -4) A dye layer with silver sulphide grains of 1.6 g of compound 8(cyan) and 2.2 g of gelatin, ~ , 5) A red-sensltised silver bromide emulsion layer of A-G 1~15 - 46 -'`' . , ~76~)6 :
1 57 g of AgBr, 1.12 g of octadecyl hydroquinone sulphonic , A acid, 0.34 g of octadecyl hydroquinone and 1.95 g of ~: gelatin, ;~ 6) A barrier layer of silver sulphide grains 1.0 g of octadecyl hydroquinone sulphonic acid and 4.0 g of gelatin, :~
7) A dye layer with silver sulphide grains of 0.94 g of : compound 7 (magent~)and 2.85 g of gelatin, .
. 8) A green-sensitised silver bromide emulsion layer of .. . .
.: 1.57 g of AgBr, 1.12 g of octadecyl hydroquinone sulphonic acid, 0.34 g of octadecyl hydroquinone and 1.95 g of .~
gelatin, .
.. 9) A barrier layer identical with layer 6), ~ .
10) A dye layer of 1.48 g o~ compound 6 (yellow) and 2.85 g of gelatin, ~, ~ 15 11) A silver bromide emulsion layer of 1.65 g of A~Br s~ 1.2 g of octadecyl hydroquinone sulphonic acid, 0.35 g of ~; octadecyl hydroquinone and 2 0 g of gelatin, and ~. 12) A protective layer of 2.6 g of gelatin.
~............... A ~trip of the image element was exposed through . . .
a colour separation wedge and subsequently processed in the ~ame way as described in Example 1. With a paste thickness of 260 ,u, a direct-positive multicoloured reproductiQn of : the original was obtained after a development time of :.:
20 minutes, ; ~ ~he following layers were applied to the substrate described in Example 1 (transparent substrate~ layers .
1, 2 and 3):
4) A dye layer of 1.25 g of oompound 1 (yellow) and 1.35 g of gelatin, 5) A blue-sensitised emulsion layer with an unfogged .. direct-positive ~ilver ohloride bromide emulsion~ silver A-G 1315 ~ 47 ~

, . ~ .

.. . . , , . , . , .,, . , ... ., .. , , ,, . , . .. " . ~ .. . . .

~ ~076~06 . covering 2.0 g, gelatin 1.8 g, and

6) A protective layer of 2 6 g of gelatin.
A strip of the photosensitive element was expo~ed and subsequently developed in conjunction with a paste bag, : 5 a cover sheet and two laterally arranged spacer strips, . .
~; in the same way as described in Example l. The spacer strips had a thickness o~ 180 y. A paste of the following : composition was used as developer: :
25 g of potassium hydroxide 5 g of N,N,Nt9N~-tetramethyl-P-phenylene diamine , ~ . , .
~: l g o~ acetyl phenyl hydrazine .~.; 1 g of paraformaldehyde 0,1 g of benzotriazole : 15 10 ml of benzyl alcohol ~ 35 g of Natrosol HHR 250 (hydroxy ethyl . cellulose) ~' ~' .
~. made up wlth water to 1000 ml.
.: A positive yellow dye image of good colour quality ~ 20 was obtained after a development time of 10 minutes.
~ EXAMPLE 8 ,, ;~ The p~ocedure was repeated as described in Example 7,~
.. ~ that, in~tead of layers 4) and 5), the following layers :~ were applied: -4~ A dye layer o~ 0.83 g of compound 2 magenta and;
1.85 g of gelatin, and , . . .
. 5) A green-sensitised emulsion layer with an unfogged .
:.~ direct-positive silver chloride bromide emulsion, silver covering 2.0 g~gelatin 1.8 g.
0 A positive magenta dye image wa~ obtained a~ter proces~ing in the same way as in Example 70 Dmin 0.38, Dmax 1. 240 . A-G 1315 - ~8 -.. ... ~ .

~ ... . ' ' ' , .

7~1)6 .

, : ~,. . .:
The procedure was repeated as described in Example 7,except that, instead of layers 4) and 5), the following layers were applied:
-- 5 4) A dye layer of 1.6 g of compound 3(cyan) and 1.2 g o~ gelatin, and ~: 5) A red-sensitised emulsion l~yer with an unfogged direct-positive silver chloride bromide emulsion, silver covering 2.0 g, gelatin 1.8 g.
A positive cyan dye image was obtained a~ter processing in the same way as in Example 7.
, ~s~e~
The procedure was repeated as described in Example 8, .. ~ except that the compound in layer 4 was replaced by c~mpounds 4, 5 and 9. Positive magenta dye images were obtained in each case after processing in the same way as in Example 7.
Example 11 ~ ~ .
The ~ollowing layers were applied to the substrate . described in Example 1(transpare~t substrate? layers 1, 2 and -~ 20 3):
4) A dye layer o~ 1.6 g of compound 8 (cyan) and 2.2 g of .t gelatin, :~.
~ 5) A red-sensitised emulsion layer with an unfogged direct-.
. positive silver chloride bromide emulsion, silver coverin ; 25 2.0 g, gelatin 1.8, g 6) A barrier layer of 0.26 g of octadecyl hydroquinone .. : sulphonic acid and 2.26 g of gelatin, .,, ~, .
7) A dye-layer of 0.94 g of compound 7 magenta and 2.85 g o~ gelatin, ~ 30 8) A green-sensitised emulsion layer with an unfogged :~ direct-po~itive silver chloride bromide emulsion, silver . covering 2.0 g, gelatin 1.8,g ~ :
-~ A-G 1315 ~ 49 ~
: .
, : ' ..

, .. . . .

~L~7~;~06 :
., ~ .
.~ . 9) A barrier layer identic~l with layer 6)~,!.'j,, 10) A dye layer of 1.48 g of compound 6 (yellow) and 2.85 g of gelatin, ~: 11) . A blue-sensitised emulsion layer with an unfogged direct-po~itive silver chloride bromide emulsion, silver ,............. ..
~^ covering 2~0 g, gelatin 1.8 g, and 12) A protective layer of 2.6 g of gelatin.
A strip of the image element was exposed through a colour separation wedge and.subsequently processed in the ~-~ 10 same way as described in Example 7. With a paste thickness of 260 ~ a direct-positive multicoloured reproduction of ~ the original was obtained after a development time of : 20 minutes~
.. EX~MPLE lZ
: 15 The following layers were applied to the substrate described in Example l (transparent substrate, layers l, 2 and 3):
4) A dye layer wi.th 0.83 g of compound.2 (magenta) and : 2.8 g of gelatin, : 20 5) A silver bromide emulsion layer of 1.6 g of AgBr and 2.0 g of gelatin) and . ~ 6) A protective layer of 2.6 g of gelatinO
The material was exposed and processed in thr same way as desoribed in Example l. A paste of the following ~k~, 25 composition was used as developer:
25 g of sodium hydroxide lO ml of benzyl alcohol ~:. 1 g of paraformaldehyde O.l g of benzotriazole 0.25g of ascorbic acid 5 g of N,N,N~,N'-tetramethyl-p-phenylene diamine 35 g of Natrosol HHR 250 ~ ' .

; ,. : ~ , ' ' ' : ,' ' '' .. - ' ' , 10~6~6 ~ . . _ made up with water to l litre~
- With a paste thicknesg of 180 ~, a magenta-coloured negative reproduction of the origi~al was obtained after : a develop~ent time of lO minutes.
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Claims (10)

What we claim is:

1. A colourphotographic material comprising at least one light-sensitive silver halide emulsion layer and, asso-ciated therewith, a non-diffusible dye-giving compound corres-ponding to the following formula in which X represents the radical of a dye or a dye precursor R1 represents -OR4 or -NHR5 where R4 is hydrogen or a radical that may be hydrolysed under the conditions of photographic development, and R5 is hydrogen or alkyl, aryl, acyl or a heterocyclic group including such alkyl, aryl, acyl and heterocyclic radicals which together with one of the substituents R2 and R3 complete a 5-, 6- or 7-membered heterocyclic ring containing at least one oxygen or nitrogen atom;
R2 represents hydrogen, alkyl, aryl or a heterocyclic group including such alkyl, aryl and heterocyclic radicals which together with one of the substituents R1 and R3 complete a 5-, 6- or 7-membered carbocyclic or heterocyclic ring, or a nitrogen carrying two substituents; the first substituent is a radical selected from the group consist-ing of hydrogen 9 alkyl, aryl and acyl including such alkyl, aryl and acyl radicals which together with R1 complete a 5-, 6- or 7-membered heterocyclic ring containing at least one nitrogen atom;
the second substituent is a radical selected from.

the group consisting of hydrogen and a radical that together with R3 com-pletes a 5-, 6- or 7-membered heterocyclic ring containing at least one ni-trogen atom; but the two substituents at the nitrogen atom are not both at the same time hydrogen; and R3 represents hydrogen, alkyl, aryl, a hetero-cyclic group, acyl, cyano or a radical that together with one of the substitu-ents R1 and R2 completes a 5-, 6- or 7-membered carbocyclic or heterocyclic ring; at least one of the substituents R1, R2 and R3 or a heterocyclic or carbocyclic ring completed by two of these substituents carries a ballasting radical; provided, however, that in the case of carbocyclic ring closure by R2 and R3 there is neither in the completed carbocylic ring nor in an aryl group represented by R5 an amino group or a hydroxyl group located in p-posi-tion to the -NR of R1; the non-diffusible dye-giving compound being oxidis-able by silver halide developer oxidation products and, when oxidised, split-table by developer alkali to release diffusible dye of the formula where X is as defined above.

2. A colour photographic material comprising at lea t one photosensi-ive silver halide en,ulsion layer and, associated therewith, a non-diffusible, dye-giving compound corresponding to the following formula:

in which X represents the radical of a dye or dye precursor; R1 represents -OR4 or NHR5 where R4 is hydrogen or a radical which can be hydrolysed under the conditions of photographic development, and R5 is hydrogen, alkyl, aryl or acyl, the acyl radical being derived from an aliphatic or aromatic car-boxylic acid or sulphonic acid; R2 represents hydrogen, alkyl with up to 22 carbon atoms, aryl or -NHR6 where R6 represents an alkyl radical or an acyl radicaly and R3 represents hydrogen, alkyl with up to 22 carbon atoms, aryl, cyano, -CO-NHR7 or -CO-OR7 where R7 is alkyl or aryl;or in which alternative-ly to the meanings defined above R1 and R2 and/or R2 and R3 or R1 and R3 to-gether may also form the atoms required to complete a heterocyclic ring, the hetero rings completed by R1 with R2 or R3 containing at least one oxygen or nitrogen atom, or in which R2 and R3 together may form the atoms required to complete a carbocyclic ring, provided, however, that in the case of carbo-cyclic ring closure by R2 and R3 there is neither in the completed carbo-cyclic ring nor in an aryl group represented by R5 an amino group or a hydro-xyl group located in p-position to the -NH of R1; the non-diffusible dye-giving compound being oxidisable by a silver halide developer oxidation products and when oxidised, splittable by developer alkali to release a dif-fusible dye of the formula:

where X is as defined above.

3. The colour photographic material as claimed in claim 1 in which the non-diffusible dye-giving compound is of the following formula II

II
in which X represents the radical or a dye or a dye precursor, R1 represents -OR4 or NHR5 where R4 is hydrogen or a radical that may be hydrolysed under the conditions of photographic development, and R5 is hydrogen or alkyl, aryl, acyl or a heterocyclic group including such alkyl, aryl, acyl and hetero-cyclic radicals which together with the substituent R6 complete a 5- or 6-membered hetorocyclic ring containing at least one oxygen or nigrogen atom;
R6 represents aryl or acyl including such aryl and acyl radicals which toge-ther with R1 complete a 5- or 6-membered heterocyclic ring; R7 represents alkyl, alkoxy, acylamino or arylamino; at least one of the substituents R6 and R7 or the heterocyclic ring completed by R1 and R6 carries a ballasting radical.

4. The colour photographic material as claimed in claim 3 in which R
and R6 complete a benzomidazoline or quinazoline ring.

5. The colour photographic material as claimed in claim 1 in which the non-diffusible dye-giving compound is of the following formula III

III

in which X represents the radical of a dye or a dye precursor, R2 represents hydrogen, alkyl, aryl or a heterocyclic group, and R8 represents one or more substituents selected from the group consisting of alkyl, alkoxy, halogen, sulfo or sulfamyl in which one or two of the hydrogens on the nitrogen may be substituted by alkyl or aryl; at least one of the substituents R2 and R8 carries a ballasting radical.

6. A colour photographic material as claimed in any of claims 1, 2 or 3, further comprising an image-receiving element adapted to produce a dye image by imagewise transfer of the diffusible dye.

7. A photographic diffusion transfer process for the production of coloured images, which comprises imagewise exposure of a colour photographic material as claimed in claim 1, and development of the exposed material with a silver halide developer, whereby the non-diffusible dye-giving compound is oxidised imagewise and split by developer alkali to produce an imagewise distribution of the diffusible dye released.

8. A compound of the following formula in which X represents the radical of a dye or a dye precursor, R1 represents -OR4 or -NHR5 where R4 is hydrogen or a radical that may be hydrolysed under the conditions or photographic development, and R5 is hydrogen or alkyl, aryl, acyl or a heterocyclic group including such alkyl, aryl, acyl and heterocyclic radicals which together with one of the substituents R2 and R3 complete a 5-, 6- or 7-membered heterocyclic ring containing at least one oxygen or nitrogen atom, R2 represents hydrogen, alkyl, aryl or a heterocyclic group including such alkyl, aryl and heterocyclic radicals which together with one of the substituents R1 and R3 complete a 5-, 6- or 7-membered carbocyclic or heterocyclic ring, or a nitrogen carrying two substituents; the first substituent is a radical selected from the group consisting of hydrogen, alkyl, aryl and acyl including such alkyl, aryl and acyl radicals which together with R1 complete a 5-, 6- or 7-membered heterocyclic ring containing at least one nitrogen atom; the second substituent is a radical selected from the group consisting of hydrogen and a radical that together with R3 completes a 5-, 6- or 7-membered heterocyclic ring containing at least one nitrogen atom; but the two substituents at the nitrogen atom are not both at the same time hydrogen; and R3 represents hydrogen, alkyl, aryl, a heterocyclic group, acyl, cyano or a radical that together with one of the substituents R1 and R2 completes a 5-, 6- or 7-membered carbocyclic or heterocyclic ring; at least one of the substituents R1, R2 and R3.
or a heterocyclic or carbocyclic ring completed by two of these substituents carries a ballasting radical, provided, however, that in the case of carbocyclic ring closure by R2 and R3 there is neither in the completed carbocyclic ring nor in an aryl group represented by R5 an amino group or a hydroxyl group located in p-position to the -NH of R1.

9. A compound of the following formula in which X represents the radical of a dye or a dye precursor; R1 represents -OR4 or -NHR5 where R4 is hydrogen or a radical that may be hydrolysed under the conditions of photographic development, and R5 is hydrogen or alkyl, aryl, acyl or a heterocyclic group including such alkyl, aryl, acyl and heterocyclic radicals which together with the substituent R6 complete a 5- or 6-membered heterocyclic ring containing at least one oxygen or nitrogen atom; R6 represents aryl or acyl including such aryl and acyl radicals which together with R1 complete a 5- or 6-membered heterocyclic ring; R7 represents alkyl, alkoxy, acylamino or aryl-amino; at least one of the substituents R6 and R7 or the heterocyclic ring completed by R1 and R6 carries a ballasting radical.

10. A compound of the following formula in which X represents the radical of a dye or a dye precusor;R2 represents hydrogen, alkyl, aryl or a heterocyclic group, and R8 represents one or more substituents selected from the group consisting of alkyl, alkoxy halogen, sulfo or sufamyl in which one or two of the hydrogens on the nitrogen may be substituted by alkyl or aryl; at least one of the substituents R2 and R8 carries a ballasting radical.