EP1037106B1

EP1037106B1 - Color diffusion transfer photographic material

Info

Publication number: EP1037106B1
Application number: EP00104590A
Authority: EP
Inventors: Nobutaka Fukagawa
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1999-03-18
Filing date: 2000-03-15
Publication date: 2005-01-26
Anticipated expiration: 2020-03-15
Also published as: EP1037106A1; DE60017623T2; JP2000330249A; DE60017623D1; ATE288092T1

Abstract

A color diffusion transfer photographic material is described which comprises a support having provided thereon at least two photosensitive silver halide emulsion layers associated with a nondiffusible dye image-forming compound which forms or releases a diffusible dye or a precursor thereof relating to silver development, or a dye image-forming compound the diffusibility of which itself changes relating to silver development, wherein said photographic material contains a compound represented by the following formula (I) and at least one oxidizing agent represented by the following formula (II), (III) or (IV): <CHEM> wherein EAG represents an electron-accepting group; N and O represent a nitrogen atom and an oxygen atom respectively, and the N-O bond cleaves when EAG accepts an electron from a reducing agent; R<1> and R<2> each represents a substituent other than a hydrogen atom, when R<1> or R<2> is bonded to -(Time)t-DIG, each represents a single bond or a divalent substituent, R<1> and R<2> may be bonded to each other to form a ring, and R<1> and EAG, or R<2> and EAG may be bonded to each other to form a ring; Time represents a group which releases DIG through the reaction following after said cleavage between nitrogen and oxygen; DIG represents a moiety which becomes a development inhibitor as a result of being released; t represents 0 or 1; and a solid line represents a bond, and a broken line represents that at least any one is bonded; <CHEM> wherein R<21>, R<22>, R<23> and R<24> each represents a hydrogen atom, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkoxyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkylthio group having from 1 to 10 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted aryloxy group, a halogen atom, or a cyano group, R<21> and R<22>, or R<23> and R<24> may be bonded to each other to form a ring; <CHEM> wherein D<1> and D<2>, which may be the same or different, each represents an atomic group necessary for forming a benzene ring or a naphthalene ring; G<1> and G<2>, which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; A<1>, A<2> and A<3>, which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; B<1>, B<2> and B<3>, which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; L<1> and L<2>, which may be the same or different, each represents a linking group; m and n each represents 0 or 1; and M<1> and M<2>, which may be the same or different, each represents a component having a function of releasing an azo compound from a compound represented by formula (III) as a result of development, or a hydrogen atom; <CHEM> wherein EAG represents an electron-accepting group; N and O represent a nitrogen atom and an oxygen atom respectively, and the N-O bond cleaves when EAG accepts an electron from a reducing agent; and R<41> and R<42> each represents a substituent other than a hydrogen atom, R<41> and R<42>, R<41> and EAG, or R<42> and EAG may be bonded to each other to form a ring.

Description

The present invention relates to a color diffusion transfer photographic material, in particular, relates to a color diffusion transfer photographic material containing a development inhibitor-releasing compound and an oxidizing agent.
In a color diffusion transfer photographic material, it is widely known to use a technique of fog prevention, in particular, to use a development inhibitor or a precursor thereof for obtaining an image having low minimum image density (hereinafter referred to as "Dmin") and high whiteness. Examples of development inhibitors (including precursors thereof) are disclosed in JP-A-50-89034 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), JP-A-54-155837, JP-A-60-95539 and JP-A-60-144737. However, the techniques of using development inhibitors disclosed in these patents have drawbacks that even necessary development is inhibited for obtaining sufficient fog-preventing effect, as a result, maximum image density (hereinafter referred to as "Dmax") of image is reduced, and delays in image appearance time and finishing time are caused. With respect to this problem, compounds of primarily releasing a development inhibitor at Dmin part are disclosed in JP-A-63-113454. That is, as the development inhibitor of these compounds is released by the reaction with a reducing agent in a processing solution, the amount of release of a development inhibitor is small where silver development is active and a reducing agent is less. However, although the reduction of Dmax can be improved with these compounds, delay in image appearance time cannot sufficiently be improved.
Lowering of Dmin is incompatible with shortening of image appearance time by the method of using a development inhibitor or a precursor alone as above. That is, even with the compounds disclosed in JP-A-63-113454, a reducing agent partly reacts with the development inhibitor precursor also at Dmax part and the development inhibitor is released hence delay in silver development and further delays of image appearance time and image-finishing time are unavoidable. This delay in image completion is a fatal problem with the instant photograph which is characterized in that an image can be observed just after photographing.
Accordingly, an object of the present invention is to provide a color diffusion transfer photographic material which is short in image appearance time and image-finishing time and exhibits high whiteness of the white background.
JP-A-08-122995 discloses a multi-layer heat developable colour photosensitive material. The photosensitive material is provided with at least a photosensitive silver halide, a binder, an electron donor and/or precursor thereof and a layer containing a dispersion-resistant compound releasing a dispersible dye by being reduced. The presence of an oxidising compound is also taught.
DE-A-3 740 849 discloses a photographic material based on colour diffusion transfer technology including the use of development inhobitor precursors of formula PWR-(TIME)_t-AF wherein PWR represents a group releasing (TIME)_t-AF upon reduction. Typical embodiments thereof employ a transparent support, a white reflective layer, a light shielding layer and a peeling-off layer.
US-4 485 164 also relates to color diffusion transfer photography.
DE-A-3 505 673 teaches a direct positive silver halide photographic material having, on a support, at least one direct positive internal latent type direct positive photosensitive silver halide emulsion containing a hydrazine nucleating agent and an aromatic compound wherein two aromatic rings are linked via -N=N- as accelerator for nucleus formation.
As a result of extensive studies for achieving the above object, the present inventors have found that the object of the present invention can be effectively attained by the following photographic material.
1) A color diffusion transfer photographic material which comprises a support having provided thereon at least two internal latent image type direct positive photosensitive silver halide emulsion layers associated with a nondiffusible dye image-forming compound which forms or releases a diffusible dye or a precursor thereof relating to silver development, or a dye image-forming compound the diffusibility of which changes itself relating to silver development, wherein the photographic material contains a compound represented by the following formula (I) and at least one oxidizing agent represented by the following formula (II), (III) or (IV):

¹

²

¹

²

_t

¹

²

¹

²

²¹

²²

²³

²⁴

²¹

²²

²³

²⁴

¹

²

¹

²

¹

²

³

¹

²

³

¹

²

¹

²

⁴¹

⁴²

⁴¹

⁴²

⁴¹

⁴²

The compound represented by formula (I) according to the present invention is a compound which is reduced by a coexisting reducing substance during processing, thereby the nitrogen-oxygen bond is cleaved, and releases a development inhibitor by the subsequent electron transfer. However, if the compound is used alone in a layer adjacent to an emulsion layer according to the method as disclosed in JP-A-63-113454, white background can be improved to a certain level by the inhibition of fog but the effect is insufficient, and if the addition amount is increased, image appearance and image-finishing are delayed. On the other hand, when the compound represented by formula (II), (III) or (IV) is used alone, although the shortening of image appearance time and the increment of Dmax can be improved to a certain level, Dmin also increases. The present inventors have found, however, that when the compound represented by formula (I) is used in combination with at least one compound represented by formula (II), (III) or (IV) as in the embodiment of the present invention, lower Dmin can be obtained as compared with the time when the compound represented by formula (I) is used alone, and an image having shorter image appearance time and higher Dmax can be obtained as compared with the time when the compound represented by formula (II), (III) or (IV) is used alone. This effect is particularly conspicuous when the compound represented by formula (I) is used in an emulsion layer in combination with at least one oxidizing agent represented by formula (II), (III) or (IV).
The compound represented by formula (I) according to the present invention will be described in detail below.
The compound represented by formula (I) is a development inhibitor-releasing compound, and to heighten characteristic thereof and to increase the degree of freedom in synthesis, the compound (I) is preferably represented by formula (Ia):
wherein R³ represents an atomic group necessary for forming a 3-to 8-membered monocyclic or condensed heterocyclic ring by bonding to a nitrogen atom and an oxygen atom; EAG, TIME, DIG and t have the same meaning as those in formula (I).
Any conventionally known development inhibitor can be used as the development inhibitor represented by DIG.
Examples of development inhibitors include compounds having a mercapto group bonding to a heterocyclic ring, e.g., substituted or unsubstituted mercaptoazoles (specifically, 1-phenyl-5-mercaptotetrazole, 1-(4-carboxyphenyl)-5-mercaptotetrazole, 1-(3-hydroxyphenyl)-5-mercaptotetrazole, 1-(4-sulfophenyl)-5-mercaptotetrazole, 1-(3-sulfophenyl)-5-mercaptotetrazole, 1-(4-sulfamoylphenyl)-5-mercaptotetrazole, 1-(3-hexanoylaminophenyl)-5-mercaptotetrazole, 1-ethyl-5-mercaptotetrazole, 1-(2-carboxyethyl)-5-mercaptotetrazole, 2-methylthio-5-mercapto-1,3,4-thiadiazole, 2-(2-carboxyethylthio)-5-mercapto-1,3,4-thiadiazole, 3-methyl-4-phenyl-5-mercapto-1,2,4-triazole, 2-(2-dimethylaminoethylthio)-5-mercapto-1,3,4-thiadiazole, 1-(4-n-hexylcarbamoylphenyl)-2-mercaptoimidazole, 3-acetylamino-4-methyl-5-mercapto-1,2,4-triazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercapto-6-nitro-1,3-benzoxazole, 1-(1-naphthyl)-5-mercaptotetrazole, 2-phenyl-5-mercapto-1,3,4-oxadiazole, 1-[3-(3-methylureido)phenyl]-5-mercaptotetrazole, 1-(4-nitrophenyl)-5-mercaptotetrazole, and 5-(2-ethylhexanoylamino)-2-mercaptobenzimidazole), substituted or unsubstituted mercaptoazaindenes (specifically, 6-methyl-4-mercapto-1,3,3a,7-tetraazaindene, 6-methyl-2-benzyl-4-mercapto-1,3,3a,7-tetraazaindene, 6-phenyl-4-mercaptotetraazainene, and 4,6-dimethyl-2-mercapto-1,3,3a,7-tetraazaindene), and substituted or unsubstituted mercaptopyrimidines (specifically, 2-mercaptopyrimidine, 2-mercapto-4-methyl-6-hydroxypyrimidine and 2-mercapto-4-propylpyrimidine).
Examples of development inhibitors further include heterocyclic compounds capable of forming an imino silver, e.g., substituted or unsubstituted benzotriazoles (specifically, benzotriazole, 5-nitrobenzotriazole, 5-methylbenzotriazole, 5,6-dichlorobenzotriazole, 5-bromobenzotriazole, 5-methoxybenzotriazole, 5-acetylaminobenzotriazole, 5-n-butylbenzotriazole, 5-nitro-6-chlorobenzotriazole, 5,6-dimethylbenzotriazole, and 4,5,6,7-tetrachlorobenzotriazole), substituted or unsubstituted indazoles (specifically, indazole, 5-nitroindazole, 3-nitroindazole, 3-chloro-5-nitroindazole, 3-cyanoindazole, 3-n-butylcarbamoylindazole, and 5-nitro-3-methanesulfonylindazole), and substituted or unsubstituted benzimidazoles (specifically, 5-nitrobenzimidazole, 4-nitrobenzimidazole, 5,6-dichlorobenzimidazole, 5-cyano-6-chlorobenzimidazole, and 5-trifluoromethyl-6-chlorobenzimidazole).
The development inhibitor may have development inhibiting property after being released from the oxidation reduction mother nucleus of the compound represented by formula (I) by the reaction subsequent to an oxidation reduction reaction in development processing step and further changes to a compound having substantially no development inhibiting property, or extremely reduced property, if at all.
Specific examples of such compounds include 1-(3-phenoxycarbonylphenyl)-5-mercaptotetrazole, 1-(4-phenoxycarbonylphenyl)-5-mercaptotetrazole, 1-(3-maleinimidophenyl)-5-mercaptotetrazole, 5-(phenoxycarbonyl)benzotriazole, 5-(p-cyanophenoxycarbonyl)benzotriazole, 2-phenoxycarbonylmethylthio-5-mercapto-1,3,4-thiadiazole, 5-nitro-3-phenoxycarbonylindazole, 5-phenoxycarbonyl-2-mercaptobenzimidazole, 5-(2,3-dichloropropyloxycarbonyl)benzotriazole, 5-benzyloxycarbonylbenzotriazole, 5-(butylcarbamoylmethoxycarbonyl)benzotriazole, 5-(butoxycarbonylmethoxycarbonyl)benzotriazole, 1-(4-benzoyloxyphenyl)-5-mercaptotetrazole, 5-(2-methanesulfonylethoxycarbonyl)-2-mercaptobenzothiazole, 1-[4-(2-chloroethoxycarbonyl)phenyl]-2-mercaptoimidazole, 2-[3-(thiophen-2-ylcarbonyl)propyl]thio-5-mercapto-1,3,4-thiadiazole, 5-cinnamoylaminobenzotriazole, 1-(3-vinylcarbonylphenyl)-5-mercaptotetrazole, 5-succinimidomethylbenzotriazole, 2-(4-succinimidophenyl)-5-mercapto-1,3,4-oxadiazole, 3-[4-(benzo-1,2-isothiazole-3-oxo-1,1-dioxy-2-yl)phenyl]-5-mercapto-4-methyl-1,2,4-triazole, and 6-phenoxycarbonyl-2-mercaptobenzoxazole.
EAG represents a group which accepts an electron from a reducing substance and is bonded to a nitrogen atom. EAG is preferably represented by the following formula (A) or (B):
In formula (A) , Q¹ represents
V_n' represents an atomic group to form a 3- to 8-membered ring together with Q¹ and Q²; n' represents an integer of from 3 to 8 , here V₃ represents -Q³- , V₄ represents -Q³-Q⁴-, V₅ represents -Q³-Q⁴-Q⁵-, V₆ represents -Q³-Q⁴-Q⁵-Q⁶-, V₇ represents -Q³-Q⁴-Q⁵-Q⁶-Q⁷-, and V₈ represents -Q³-Q⁴-Q⁵-Q⁶-Q⁷-Q⁸-.
Q², Q³, Q⁴, Q⁵, Q⁶, Q⁷ and Q⁸ each represents -C(Sub)₂-, -N(Sub)-, -O-, -S- or -SO₂-, Sub represents a single bond (a κ bond), a hydrogen atom, or a substituent shown below. Sub may be the same with each other or may be different from each other and may be bonded to each other to form a 3- to 8-membered saturated or unsaturated carbocyclic ring or heterocyclic ring. In formula (A), Sub is selected so that the total of a Hammett's substituent constant σ_p of the substituent preferably becomes +0.09 or more, more preferably +0.3 or more, and most preferably +0.45 or more.
Examples of the substituents represented by Sub include the following groups and each group preferably has from 0 to 40 carbon atoms: a substituted or unsubstituted alkyl group (e.g., methyl, ethyl, sec-butyl, t-octyl, benzyl, cyclohexyl, chloromethyl, dimethylaminomethyl, n-hexadecyl, trifluoromethyl, 3,3,3-trichloropropyl, methoxycarbonylmethyl, etc.), a substituted or unsubstituted alkenyl group (e.g., vinyl, 2-chlorovinyl, 1-methylvinyl, etc.), a substituted or unsubstituted alkynyl group (e.g., ethynyl, 1-propynyl, etc.), a cyano group, a nitro group, a halogen atom (e.g., fluorine, chlorine, bromine, iodine), a substituted or unsubstituted heterocyclic residue (e.g., 2-pyridyl, 1-imidazolyl, benzothiazol-2-yl, morpholino, benzoxazol-2-yl, etc.), a sulfo group, a carboxyl group, a substituted or unsubstituted aryloxycarbonyl or alkoxycarbonyl group (e.g., methoxycarbonyl, ethoxycarbonyl, tetradecyloxycarbonyl, 2-methoxyethylcarbonyl, phenoxycarbonyl, 4-cyanophenylcarbonyl, 2-chlorophenoxycarbonyl, etc.), a substituted or unsubstituted carbamoyl group (e.g., carbamoyl, methylcarbamoyl, diethylcarbamoyl, methylhexadecylcarbamoyl, methyloctadecylcarbamoyl, phenylcarbamoyl, 2,4,6-trichlorophenylcarbamoyl, N-ethyl-N-phenylcarbamoyl, 3-hexadecylsulfamoylphenylcarbamoyl, etc.), a hydroxyl group, a substituted or unsubstituted azo group (e.g., phenylazo, p-methoxyphenylazo, 2-cyano-4-methanesulfonylphenylazo, etc.), a substituted or unsubstituted aryloxy or alkoxyl group (e.g., methoxy, ethoxy, dodecyloxy, benzyloxy, phenoxy, 4-methoxyphenoxy, 3-acetylaminophenoxy, 3-methoxycarbonylpropyloxy, 2-trimethylammonioethoxy, etc.), a sulfino group, a sulfeno group, a mercapto group, a substituted or unsubstituted acyl group (e.g., acetyl, trifluoroacetyl, n-butyryl, t-butyryl, benzoyl, 2-carboxybenzoyl, 3-nitrobenzoyl, formyl, etc.), a substituted or unsubstituted arylthio or alkylthio group (e.g., methylthio, ethylthio, t-octylthio, hexadecylthio, phenylthio, 2,4,5-trichlorothio, 2-methoxy-5-t-octylphenylthio, 2-acetylaminophenylthio, etc.), a substituted or unsubstituted aryl group (e.g., phenyl, naphthyl, 3-sulfophenyl, 4-methoxyphenyl, 3-lauroylaminophenyl, etc.), a substituted or unsubstituted sulfonyl group (e.g., methylsulfonyl, chloromethylsulfonyl, n-octylsulfonyl, n-hexadecylsulfonyl, sec-octylsulfonyl, p-toluenesulfonyl, 4-chlorophenylsulfonyl, 4-dodecylphenylsulfonyl, 4-dodecyloxyphenylsulfonyl, 4-nitrophenylsulfonyl, etc.), a substituted or unsubstituted sulfinyl group (e.g., methylsulfinyl, dodecylsulfinyl, phenylsulfinyl, 4-nitrophenylsulfinyl, etc.), a substituted or unsubstituted amino group (e.g., methylamino, diethylamino, methyloctadecylamino, phenylamino, ethylphenylamino, 3-tetradecylsulfamoylphenylamino, acetylamino, trifluoroacetylamino, N-hexadecylacetylamino, N-methylbenzoylamino, methoxycarbonylamino, phenoxycarbonylmethylamino, N-methoxyacetylamino, amidinoamino, phenylaminocarbonylamino, 4-cyanophenylaminocarbonylamino, N-ethylethoxycarbonylamino, N-methyldodecylsulfonylamino, N-(2-cyanoethyl)-p-toluenesulfonylamino, hexadecylsulfonylamino, trimethylammonio,etc.), a substituted or unsubstituted sulfamoyl group (e.g., dimethylsulfamoyl, hexadecylsulfamoyl, sulfamoyl, methyloctadecylsulfamoyl, methylhexadecylsulfamoyl, 2-cyanoethylhexadecylsulfamoyl, phenylsulfamoyl, N-(3,4-dimethylphenyl)-N-octylsulfamoyl, dibutylsulfamoyl, dioctadecylsulfamoyl, bis(2-methoxycarbonylethyl)sulfamoyl, etc.), a substituted or unsubstituted acyloxy group (e.g., acetoxy, benzoyloxy, decyloyloxy, chloroacetoxy, etc.), and a substituted or unsubstituted sulfonyloxy group (e.g., methylsulfonyloxy, p-toluenesulfonyloxy, p-chlorophenylsulfonyloxy, etc.).
In formula (B), n'' represents an integer of from 1 to 6, here U₁ represents -Y¹, U₂ represents -Y¹-Y², U₃ represents -Y¹-Y²-Y³, U₄ represents -Y¹-Y²-Y³-Y⁴, U₅ represents -Y¹-Y²-Y³-Y⁴-Y⁵, and U₆ represents -Y¹-Y²-Y³-Y⁴-Y⁵-Y⁶.
Y¹, Y², Y³, Y⁴, Y⁵ and Y⁶ each represents -C(Sub')₃ or -N(Sub')₂.
Sub' represents a single bond (a σ bond, a κ bond) or the same substituents as the substituents for Sub described in formula (A). In formula (B), Sub' is selected so that the total of a Hammett's substituent constant σ_p of the substituent preferably becomes +0.09 or more, more preferably +0.3 or more, and most preferably +0.45 or more.
Specific examples of EAG include an aryl group substituted with at least one electron-attractive group (e.g., 4-nitrophenyl, 2-nitro-4-N-methyl-N-octadecylsulfamoylphenyl, 2-N,N-dimethylsulfamoyl-4-nitrophenyl, 2-cyano-4-octadecylsulfonylphenyl, 2,4-dinitrophenyl, 2,4,6-tricyanophenyl, 2-nitro-4-N-methyl-N-octadecylcarbamoylphenyl, 2-nitro-5-octylthiophenyl, 2,4-dimethanesulfonylphenyl, 3,5-dinitrophenyl, 2-chloro-4-nitro-5-methylphenyl, 2-nitro-3,5-dimethyl-4-tetradecylsulfonylphenyl, 2,4-dinitronaphthyl, 2-ethylcarbamoyl-4-nitrophenyl, 2,4-bis-dodecylsulfonyl-5-trifluoromethylphenyl, 2,3,4,5,6-pentafluorophenyl, 2-acetyl-4-nitrophenyl, 2,4-diacetylphenyl, 2-nitro-4-trifluoromethylphenyl, etc.) , a substituted or unsubstituted heterocyclic group (e.g., 2-pyridyl, 2-pyrazyl, 5-nitro-2-pyridyl, 5-N-hexadecylcarbamoyl-2-pyridyl, 4-pyridyl, 3,5-dicyano-2-pyridyl, 5-dodecylsulfonyl-2-pyridyl, 5-cyano-2-pyrazyl, 4-nitrothiophenin-2-yl, 5-nitro-1,2-dimethylimidazol-4-yl, 3,5-diacetyl-2-pyridyl, 1-dodecyl-5-carbamoylpyridinium-2-yl, etc.), and a substituted or unsubstituted quinones (e.g., 1,4-benzoquinon-2-yl, 3,5,6-trimethyl-1,4-benzoquinon-2-yl, 3-methyl-1,4-naphthoquinon-2-yl, 3,6-dimethyl-5-hexadecylthio-l,4-benzoquinon-2-yl, 5-pentadecyl-1,2-benzoquinon-4-yl, etc.). Vinylogs of these compounds and, in addition, a nitroalkyl group (e.g., 2-nitro-2-propyl), a nitroalkenyl group (e.g., 2-nitroethenyl), and a monovalent group of an α-diketo compound (e.g., 2-oxopropanoyl) can be exemplified.
R¹ and R², which may be the same or different, each represents a substituent other than a hydrogen atom, and preferred examples of the substituents include an alkyl group, an aryl group, a heterocyclic ring, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, an aryloxycarbonyl group and a sulfamoyl group. These groups may further be substituted with other groups. R¹ and R² each represents an atomic group necessary for forming a 3- to 8-membered heterocyclic ring by bonding to a nitrogen atom and an oxygen atom.
R³ represents an atomic group necessary for forming a 3-to 8-membered heterocyclic ring by bonding to a nitrogen atom and an oxygen atom as described above. Examples of the heterocyclic rings are shown below.

wherein R¹¹, R¹² and R¹³ each represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, or - (Time)_t-DIG.
The compound represented by formula (Ia) is preferably represented by formula (Ib) for further exhibiting sufficient characteristics as a positive-forming compound:
EAG, Time, t and DIG have the same meaning as described above; X represents a divalent linking group, particularly preferably represents -C(=O)- or -SO₂-.
R⁴ and R⁵ each represents a hydrogen atom or a substitutable group, and R⁴ and R⁵ may be bonded to each other to form a saturated or unsaturated carbocyclic ring or a heterocyclic ring.
R⁴ preferably represents a hydrogen atom, a substituted or unsubstituted alkyl group (e.g., methyl, ethyl, t-butyl, octadecyl, phenethyl, carboxymethyl, etc.), a substituted or unsubstituted aryl group (e.g., phenyl, 3-nitrophenyl, 4-methoxyphenyl, 4-acetylaminophenyl, 4-methanesulfonylphenyl, 2,4-dimethylphenyl, 4-tetradecyloxyphenyl,
etc.), or a substituted or unsubstituted heterocyclic group (e.g., 2-pyridyl, 2-furyl, 3-pyridyl, etc.).
R⁵ preferably represents a hydrogen atom, a substituted or unsubstituted alkyl group (e.g., methyl, hydroxymethyl,
etc.), a substituted or unsubstituted aryl group (e.g., phenyl, 4-chlorophenyl, 2-methylphenyl,

etc.), or a substituted or unsubstituted heterocyclic group (e.g., 4-pyridyl, etc.). Examples of condensed rings formed by R⁴ and R⁵ are shown below.

(Condensed rings are shown as a whole).
- (Time)_t-DIG will be described in detail below.
Time represents a group which releases DIG through the reaction following the cleavage of a nitrogen-oxygen single bond. t represents 0 or 1.
As the groups represented by Time, those represented by the following formulae (T-1) to (T-10) are preferred, wherein (*) represents the part to be bonded to a broken line and (*)(*) represents the part to be bonded to DIG.
wherein Z¹ represents (*)―O― ,
(*)―O―CH₂―O―, (*)-O-CH₂-, (*)-O-CH₂-S-,

(*)―S―,

wherein R⁶ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group.
X¹ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, ―O―R⁷, ―SR⁷,

- COOR⁷,

―CO―R⁷ , ―SO₂―R⁷, a cyano group, a halogen atom (e.g., fluorine, chlorine, bromine, iodine) or a nitro group. R⁷ and R⁸ may be the same or different and each represents the same group as R⁶. X² represents the same group as described in R⁶.
a represents an integer of from 1 to 4. When a represents 2 or more, the substituents represented by X¹ may be the same or different. When a represents 2 or more, two or more X¹'s may be bonded to each other to form a ring.
b represents 0, 1 or 2.
The groups represented by formula (T-1) are disclosed, for example, in U.S. Patent 4,248,962.
wherein Z¹, X¹, X², and a each has the same meaning as defined in formula (T-1). (*)-Z²-(CH₂)_c-N(X²)-C(=O)-(*)(*) wherein Z² represents (*)-O-, (*)-O-C(=O)-, (*)-O-C(=O)-N(R⁶)-, (*)-S-, (*)-N(R⁶)-SO₂-, (*)-N(R⁶)-CO-, (*)-O-N(R⁶)-SO₂-, (*)-N(SO₂R⁶)-, (*)-N(COR⁶)-, (*)-O-C(=O)-O-, (*)-O-C(=O)-S- or (*)-O-N(R⁶)-C(=O)-.
c represents an integer of from 1 to 4, preferably 1, 2 or 3.
R⁶ and X² each has the same meaning as defined in formula (T-1).
wherein Z³ represents (*)-O-, (*)-O-C(=O)-, (*)-N (SO₂R⁶)-, (*)-O-C(=O)-N(R⁶)-, (*)-S-, (*)-N(COR⁶)-, (*)-O-C(=O)-S-, (*)-O-CH₂-O- or (*)-O-CH₂-S-.
R⁶, R⁷, R⁸, X¹ and a have the same meaning as defined in formula (T-1). Examples of the groups represented by formula (T-4) are the timing groups disclosed in U.S. Patent 4,409,323.
wherein Z³, R⁷ , R⁸, X¹ and a have the same meaning as defined in formula (T-4).
wherein X³ represents an atomic group necessary to form a 5- to 7-membered heterocyclic ring and comprises a combination of one or more atoms selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. This heterocyclic ring may further be condensed with a benzene ring, or a 5- to 7-membered heterocyclic ring. Preferred examples of heterocyclic rings include pyrrole, pyrazole, imidazole, triazole, furan, oxazole, thiophene, thiazole, pyridine, pyridazine, pyrimidine, pyrazine, azepine, oxepine, indole, benzofuran, and quinoline.
Z³ , X¹, a, R⁷ and R⁸ have the same meaning as defined in formula (T-4). Examples of the groups represented by formula (T-6) are timing groups disclosed in British Patent 2,096,783.
wherein X⁵ represents an atomic group necessary to form a 5- to 7-membered heterocyclic ring and comprises a combination of one or more atoms selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. X⁶ and X⁷ each represents -C(R⁹)= or -N=, wherein R⁹ represents a hydrogen atom, an aliphatic group or an aromatic group. This heterocyclic ring may further be condensed with a benzene ring, or a 5- to 7-membered heterocyclic ring.
Preferred examples of heterocyclic rings include pyrrole, imidazole, triazole, furan, oxazole, oxadiazole, thiophene, thiazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, azepine, oxepine, and isoquinoline.
Z³ has the same meaning as defined in formula (T-4).
wherein X¹⁰ represents an atomic group necessary to form a 5- to 7-membered heterocyclic ring and comprises a combination of one or more atoms selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. X⁸ and X⁹ each represents
or >N-. This heterocyclic ring may further be condensed with a benzene ring, or a 5- to 7-membered heterocyclic ring.
X¹, X², a and b have the same meaning as defined in formula (T-1).
Z³ has the same meaning as defined in formula (T-4).
wherein X¹¹ has the same meaning as X¹⁰ defined in formula (T-8). Z³ has the same meaning as defined in formula (T-4). d represents 0 or 1. Preferred examples of heterocyclic rings are shown below.

wherein X¹ and a have the same meaning as defined in formula (T-1). X¹² represents a hydrogen atom, an aliphatic group, an aromatic group, an acyl group, a sulfonyl group, an alkoxycarbonyl group, a sulfamoyl group, a heterocyclic group, or a carbamoyl group.
wherein X¹ and X² have the same meaning as defined in formula (T-1), and Z³ has the same meaning as defined in formula (T-4). c has the same meaning as defined in formula (T-3), and preferably 1 or 2.
In the above formulae (T-1) to (T-10), when each of X¹, X², R⁶, R⁷, R⁸ and R⁹ contains the moiety of an aliphatic group, the aliphatic group is preferably an aliphatic group having from 1 to 20 carbon atoms, and may be saturated or unsaturated, substituted or unsubstituted, acyclic or cyclic, linear or branched. When each of X¹, X², R⁶, R⁷, R⁸ and R⁹ contains the moiety of an aromatic group, the aromatic group is preferably an aromatic group having from 6 to 20, more preferably from 6 to 10 carbon atoms, and furthermore preferably a substituted or unsubstituted phenyl group. When each of X¹, X², R⁶, R⁷, R⁸ and R⁹ contains the moiety of a heterocyclic group, the heterocyclic group is preferably a 5- or 6-membered heterocyclic group containing at least one nitrogen atom, oxygen atom or sulfur atom as a hetero atom. Examples of preferred heterocyclic groups include a pyridyl group, a furyl group, a thienyl group, a triazolyl group, an imidazolyl group, a pyrazolyl group, a thiadiazolyl group, an oxadiazolyl group and a pyrrolidinyl group.
Examples of preferred timing groups are shown below.
Examples of the compounds represented by formula (I) are shown below.
The compound represented by formula (II) will be described in detail below.
As the examples of the substituents of the alkyl groups or alkyl group residues represented by R²¹, R²², R²³ and R²⁴, a hydroxyl group and a sulfonamido group can be exemplified. As the examples of the substituents of the aryl groups or aryl group residues represented by R²¹, R²², R²³ and R²⁴, an alkyl group having from 1 to 5 carbon atoms can be exemplified. As the examples of the rings formed by R²¹ and R²² or R²³ and R²⁴ by bonding to each other, a 5- or 6-membered ring (e.g., a benzene ring, and this ring may have an unsubstituted group such as an alkyl group) can be exemplified.
Specific examples of the compounds represented by formula (II) are shown below.
The compound represented by formula (III) will be described in detail below.
Examples of the substituents represented by G¹, G², A¹, A², A³, B¹, B² and B³ which do not cause photographically maleficent influences include a halogen atom, a nitro group, a cyano group, an alkyl group, a substituted alkyl group, an alkoxyl group, a substituted alkoxyl group, a group represented by -NHCOR³¹ (wherein R³¹ represents an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, or a substituted aralkyl group), -NHSO₂R³¹ (R³¹ has the same meaning as above) , -SOR³¹ (R³¹ has the same meaning as above) , -SO₂R³¹ (R³¹ has the same meaning as above), -COR³¹ (R³¹ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³, which may be the same or different, each represents a hydrogen atom, an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, or a substituted aralkyl group), -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above), an amino group (which may be substituted with an alkyl group), and a group which forms a hydroxyl group by hydrolysis.
Examples of the substituents of the above substituted alkyl group, substituted alkoxyl group, substituted phenyl group, and substituted aralkyl group include an amino group, a hydroxyl group, a nitro group, an alkoxyl group having from 1 to about 4 carbon atoms, a group represented by -NHSO₂R³¹ (R³¹ has the same meaning as above), -NHCOR³¹ (R³¹ has the same meaning as above), -SO₂(R³²)(R³³) (R³² and R³³ have the same meaning as above), -CON(R³²)(R³³), (R³² and R³³ have the same meaning as above), -SO₂R³¹ (R³¹ has the same meaning as above), -COR³¹ (R³¹ has the same meaning as above), a halogen atom, a cyano group, and an amino group (which may be substituted with an alkyl group).
A linking group represented by L¹ and L² is preferably represented by -[J¹-K¹-(J²-K²)_p-(J³-K³)_q-]_r-, wherein J¹, J² and J³, which may be the same or different, each represents -CO-, -SO₂-, -CON(R³²)- (R³² has the same meaning as above) , -SO₂N(R³²)- (R³² has the same meaning as above), -N (R³²)-CO- (R³² has the same meaning as above), -N(R³²)-SO₂- (R³² has the same meaning as above), -N(R³²)-R³⁴- (R³² has the same meaning as above, and R³⁴ represents an alkylene group having from 1 to about 4 carbon atoms), -N(R³²)-R³⁴-N(R³³)- (R³², R³³ and R³⁴ have the same meaning as above), -O-, -S-, -N(R³²)-CO-N(R³³)- (R³² and R³³ have the same meaning as above), or -N(R³²)-SO₂-N(R³³)- (R³² and R³³ have the same meaning as above).
K¹, K² and K³, which may be the same or different, each represents an alkylene group, a substituted alkylene group, an arylene group, a substituted arylene group, an aralkylene group, or a substituted aralkylene group.
The substituents of these substituted alkylene group, substituted arylene group, and substituted aralkylene group can be selected from the atoms and groups described above.
p, q and r each represents 0 or 1.
m and n each represents 0 or 1.
Of the compounds represented by formula (III), preferred compounds are as follows.
D¹ and D², which may be the same or different, each represents an atomic group necessary to form a benzene ring or a naphthalene ring.
At least one of G¹ and G² represents an electron-attractive atom or group having a Hammett's σ value of the same with or higher than that of a fluorine atom, and specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, an alkylsulfonyl group, a sulfamoyl group, a sulfonamido group, and a carbamoyl group. A Hammett's σ value is described in J. Org. Chem., Vol. 23, p. 420 (1958). When either of G¹ or G² represents the above-described electron-attractive atom or group, the other represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, a cyano group, a nitro group, -SO₂R³¹ (R³¹ has the same meaning as above), -NHCOR³¹ (R³¹ has the same meaning as above), -NHSO₂R³¹ (R³¹ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above).
A¹, A² and A³, which may be the same or different, each represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, -NHCOR³¹ (R³¹ has the same meaning as above), -NHSO₂R³¹ (R³¹ has the same meaning as above), -SO₂R³¹ (R³¹ has the same meaning as above), -CON (R³²) (R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above).
B¹, B² and B³, which may be the same or different, each represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group, an alkoxyl group, -SO₂R³¹ (R³¹ has the same meaning as above), -CON (R³²) (R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above).
J¹, J² and J³, which may be the same or different, each represents -CO-, -SO₂-, -CONH-, -SO₂NH-, -NHCO- or -NHSO₂-.
K¹, K² and K³, which may be the same or different, each represents an alkylene group, an arylene group, or a substituted arylene group.
p, q and r each represents 0 or 1.
Of the compounds represented by formula (III), particularly preferred compounds are as follows.
D¹ represents an atomic group necessary to form a benzene ring or a naphthalene ring, and D² represents an atomic group necessary to form a benzene ring.
At least one of G¹ and G² represents a halogen atom (in particular, a chlorine atom) , and when either one alone of G¹ or G² represents a halogen atom, the other represents a hydrogen atom, an alkyl group, or an alkoxyl group.
A¹, A² and A³, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, a cyano group, -NHCOR³⁵ (R³⁵ represents an alkyl group or a phenyl group), -NHSO₂R³⁵ (R³⁵ has the same meaning as above), -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above).
B¹, B² and B³, which may be the same or different, each represents a hydrogen atom, a cyano group, a halogen atom, a nitro group, an alkyl group, -SO₂R³⁵ (R³⁵ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above).
J¹ and J², which may be the same or different, each represents -CO-, -SO₂-, -CONH-, -SO₂NH-, -NHCO- or -NHSO₂-.
K¹ and K², which may be the same or different, each represents a phenylene group, a substituted phenylene group, or an alkylene group.
p and r each represents 0 or 1, and q represents 0.
A nitro group to be substituted in a benzene ring completed by D¹ and D² is preferably positioned at the p-position or o-position of the azo group.
When M¹ and M² each represents a group other than a hydrogen atom, a specific preferred example is a group represented as (ballast)-(a redox-cleaving atomic group)-.
(Ballast)- is a group for substantially immobilizing the compound represented by formula (III) in a photographic layer.
-(A redox-cleaving atomic group)- has a property to be cut by oxidation or reduction by heat or under an alkaline condition, or a property of separating an azo compound moiety bonded thereto by cyclization, etc.
Redox-cleaving atomic groups disclosed in the following patents are effectively used in the present invention, that is, U.S. Patents 3,928,312, 3,993,638, 4,076,529, 4,152,153, 4,055,428, 4,053,312, 4,198,235, 4,179,291, 4,149,892, 3,844,785, 3,443,943, 3,751,406, 3,443,939, 3,443,940, 3,628,952, 3,980,479, 4,183,753, 4,142,891, 4,278,750, 4,139,379, 4,218,368, 3,421,964, 4,199,355, 4,199,354, 4,278,750, 4,135,929, 4,336,322, 4,371,604, 4,139,389, JP-A-53-50736, JP-A-52-4819, JP-A-51-104343, JP-A-54-130122, JP-A-53-110827, JP-A-56-12642, JP-A-56-16131, JP-A-57-4043, JP-A-57-650, JP-A-57-20735, JP-A-53-69033, JP-A-54-130927, JP-A-56-164342, and JP-A-57-119345.
The representative example of the redox-cleaving atomic group is an N-substituted sulfamoyl group.
Specific examples of the compounds represented by formula (III) are shown below.
wherein A¹¹ represents H.
III-2. In formula III-1, A¹¹ represents Cl.
III-3. In formula III-1, A¹¹ represents -NHCOCH₃.
III-4. In formula III-1 , A¹¹ represents -NHSO₂CH₃.
III-5. In formula III-1, A¹¹ represents CN.
III-6. In formula III-1 , A¹¹ represents -SO₂N(iso-C₃H₇)₂.
111-7. In formula III-1, A¹¹ represents -CON(C₂H₅)₂.
wherein K¹¹ represents
M¹¹ represents
III-9. In formula III-8, K¹¹ represents -C₁₆H₃₂-, M¹¹ represents H.

wherein B¹¹ represents H.
III-13. In formula III-12, B¹¹ represents -NO₂.
III-14. In formula III-12, B¹¹ represents -Cl.
III-15. In formula III-12, B¹¹ represents -CN.
III-16. In formula III-12, B¹¹ represents -Br.
The compound represented by formula (IV) will be described in detail below.
R⁴¹ and R⁴², which may be the same or different, each represents a substituent other than a hydrogen atom, and preferred examples of the substituents include an alkyl group, an aryl group, a heterocyclic ring, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, an aryloxycarbonyl group and a sulfamoyl group. These groups may further be substituted with other groups.
In general, a reduction potential can be increased by making the substituent of an oxygen atom or a nitrogen atom electron attractive. The same tendency is also applicable to the substituent of an electron-accepting group. The larger the electron-attractive property, the higher is the reduction potential (oxidizing property).
As the compound for use in the above-described use, the compound represented by formula (IV) is preferably the compound represented by formula (IVa) to further heighten the characteristics as the oxidizing agent (e.g., reduction potential), the stability of the compound and the degree of freedom in synthetic design:
wherein R⁴³ represents an atomic group necessary to form a 3- to 8-membered monocyclic or condensed heterocyclic ring together with a nitrogen atom and an oxygen atom, R⁴³ may be bonded to EAG to form a ring.
Other meaning of formula (IVa) is the same as defined in formula (IV) but further described in detail below.
EAG is a group which accepts an electron from a reducing substance and is bonded to a nitrogen atom. EAG is preferably represented by formula (A) or (B) described in formula (I).
As described above, R⁴³ represents an atomic group necessary to form a 3- to 8-membered heterocyclic ring together with a nitrogen atom and an oxygen atom. Examples of such heterocyclic rings are shown below.

wherein R⁴⁶, R⁴⁷ and R⁴⁸, which may be the same or different, each represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, an aryloxycarbonyl group, a sulfamoyl group, a cyano group, a nitro group, a halogen atom, an amino group, an alkoxyl group, an aryloxy group, a hydroxyl group, a ureido group, an aminocarbonyloxy group, an alkoxycarbonylamino group, an amido group, a sulfo group, a carboxyl group, a sulfonamido group, an acyloxy group or an aryloxycarbonylamino group.
Of the compounds represented by formula (IVa), the compound represented by formula (IVb) can be exemplified as an example having further sufficient characteristics as the oxidative compound.
EAG is as defined above. X' represents a divalent linking group, and particularly preferably represents -C(=O)- or -SO₂-.
R⁴⁴ and R⁴⁵ each represents a hydrogen atom or a group substitutable with a hydrogen atom, and they may be bonded to each other to form a saturated or unsaturated carbocyclic ring or heterocyclic ring.
Preferred examples of the substituents of R⁴⁴ and R⁴⁵ include a hydrogen atom, a substituted or unsubstituted alkyl group (e.g., methyl, ethyl, t-butyl, octadecyl, phenethyl, carboxymethyl, etc.), a substituted or unsubstituted aryl group (e.g., phenyl, 3-nitrophenyl, 4-methoxyphenyl, 4-acetylaminophenyl, 4-methanesulfonylphenyl, 2,4-dimethylphenyl, 4-tetradecyloxyphenyl, etc.), a substituted or unsubstituted heterocyclic group (e.g., 2-pyridyl, 2-furyl, 3-pyridyl, etc.), an acyl group (e.g., acetyl, benzoyl, dodecanoyl, 4-acetamidobenzoyl, etc.), an alkoxycarbamoyl group (e.g., methoxycarbonyl, methoxyethoxycarbonyl, butoxycarbonyl, etc.), a carbamoyl group (e.g., carbamoyl, ethylcarbamoyl, phenylcarbamoyl, diethylcarbamoyl, dodecylcarbamoyl, etc.), a sulfonyl group (e.g., methanesulfonyl, p-toluenesulfonyl, hexadecylsulfonyl, etc.), an aryloxycarbonyl group (e.g., phenoxycarbonyl, naphthyloxycarbonyl, etc.), a sulfamoyl group (e.g., dimethylsulfamoyl, butylsulfamoyl, phenylsulfamoyl, etc.), a cyano group, a nitro group, a halogen atom (e.g., F, Cl, Br, I, etc.), an amino group (e.g., amino, methylamino, diethylamino, methylphenylamino, 1-pyrrolidino, etc.), an alkoxyl group (e.g., methoxy, ethoxy, octyloxy, isopropyloxy, etc.), an aryloxy group (e.g., phenoxy, 4-chlorophenoxy, 3-pentadecylphenoxy, etc.), a hydroxyl group, a ureido group (e.g., 3-methylureido, 3,3-diethylureido, 1-methyl-3-phenylureido, etc.), an aminocarbonyloxy group (e.g., dibutylaminocarbonyloxy, phenylaminocarbonyloxy, cyclohexylaminocarbonyloxy, etc.), an alkoxycarbonylamino group (e.g., methoxycarbonylamino, hexyloxycarbonylamino, etc.), an amido group (e.g., acetamido, benzamido, etc.), a sulfo group or a salt thereof, a carboxyl group or a salt thereof, a sulfonamido group (e.g., methanesulfonamido, phenylsulfonamido, dodecylsulfonamido, etc.), an acyloxy group (e.g., acetoxy, benzoyloxy, etc.), and an aryloxycarbonylamino group (e.g., phenoxycarbonylamino, etc.).
Examples of condensed rings formed by R⁴⁴ and R⁴⁵ by forming a ring are shown below.
(Condensed rings are shown as a whole).
Specific examples of the compounds represented by formula (IV) are shown below but it should not be construed as the present invention is limited thereto.

wherein
represents

represents -CH₂-CH₂-CH₂-
represents
The compounds represented by formulae (I), (II), (III) and (IV) according to the present invention are preferably contained in a layer containing silver halide or an adjacent layer thereto, and most preferably contained in a silver halide emulsion layer.
The compounds represented by formulae (I), (II), (III) and (IV) according to the present invention can be added to photographic layers according to well-known methods, e.g., a method disclosed in U.S. Patent 2,322,027. In this case, arbitrary high boiling point organic solvents or low boiling point organic solvents can be used.
The addition amount is generally from 0.05 to 5 mmol/m², preferably from 0.1 to 1 mmol/m².
The molar ratio of the compound represented by formula (II), (III) or (IV) to the compound represented by formula (I) according to the present invention is preferably from 0.1 to 10, more preferably from 0.5 to 5.
In the present invention, a reducing substance is combined with the compound represented by formula (I). A reducing substance may be contained in advance in any layer on the same support on which the layer containing the compound (I) is provided, may be contained in a layer on a different support from the support on which the layer containing the compound (I) is provided or, alternatively, may be contained in a treating solution (an alkali treating composition). In any case, a reducing substance is used so as to come into contact with the compound (I) and works to reduce the compound (I). The kind and amount of a reducing substance are not particularly restricted and any substance can be used so long as it can reduce the compound (I).
As preferred reducing substances, hydroquinones, aminophenols, aminonaphthols, 3-pyrazolidinones, saccharins and precursors thereof, picoliniums, and compounds disclosed in JP-A-53-110827 as an electron-donating compound can be exemplified.
Specific examples of reducing substances are shown below.
In the present invention, when a reducing substance which reduces the compound (I) is contained on the same support as the compound (I), they are preferably contained in the same layer or adjacent layers.
On the other hand, examples of reducing substances which can be contained in a treating solution include alkali-soluble reducing substances such as ordinary developing agents, hydroquinones, and inorganic reducing agents. Many of these reducing substances are often used for other functions but in the present invention they can be used also by uniting a function of reducing substances of compound (I). For instance, a developing agent such as phenidone can also be used as a reducing substance of compound (I) according to the present invention in addition to the functions of from silver development to the cross oxidation of a dye-donating redox compound.
The color diffusion transfer photographic material according to the present invention will be described below.
A typical form of a color diffusion transfer film unit is a form in which an image-receiving element and a photosensitive element are laminated on one transparent support, and the photosensitive element is not necessary to be peeled off from the image-receiving element after completion of a transferred image. More specifically, the image-receiving element comprises at least one mordant layer, and a preferred mode of the photosensitive element is constituted by combining a blue-sensitive emulsion layer, a green-sensitive emulsion layer and a red-sensitive layer, or a green-sensitive emulsion layer, a red-sensitive emulsion layer and an infrared-sensitive emulsion layer, or a blue-sensitive emulsion layer, a red-sensitive emulsion layer and an infrared-sensitive emulsion layer with a combination of a yellow dye image-forming compound, a magenta dye image-forming compound and a cyan dye image-forming compound, in such a manner that the three emulsion layers comprise the three dye image-forming compounds, respectively ("an infrared-sensitive emulsion layer" used herein means an emulsion layer having spectral sensitivity maximum to light of a wavelength of 700 nm or more, in particular, 740 nm or more). A white reflective layer containing a solid pigment such as titanium oxide is provided between the mordant layer and the photosensitive layer or between the mordant layer and the layer containing the dye image-forming compound so as to be able to view the transferred image through the transparent support.
A light-shielding layer may further be provided between the white reflective layer and the photosensitive layer so as to make it possible to complete development processing in daylight. Also, a peeling-off layer may be provided in an appropriate position so as to be able to peel off all or a part of the photosensitive element from the image-receiving element, if desired. Such modes are disclosed, for example, in JP-A-56-67840 and Canadian Patent 674,082.
As another embodiment of a peeling-off mode of a lamination type, JP-A-63-226649 discloses a color diffusion transfer photographic film unit comprising a white support having provided thereon a photosensitive element comprising at least (a) a layer having a neutralization function, (b) a dye image-receiving layer, (c) a peeling-off layer and (d) at least one silver halide emulsion layer associated with a dye image-forming compound in this order, an alkali treating composition containing a light-shielding agent, and a transparent cover sheet, which film unit further comprises a layer having a light-shielding function on the side opposite to the side on which the treating composition of the emulsion layer is developed.
Further, in another form in which peeling-off is unnecessary, the above-described photosensitive element is coated on a transparent support, a white reflective layer is provided thereon, and an image-receiving layer is further laminated thereon. An embodiment in which an image-receiving element, a white reflective layer, a peeling-off layer and a photosensitive element are laminated on the same support and the photosensitive element is intentionally peeled off from the image-receiving element is disclosed in U.S. Patent 3,730,718.
On the other hand, typical forms in which a photosensitive element and an image-receiving element are separately coated on two supports, respectively, may be divided broadly into two types. One is a peeling-off type and the other is a peeling-off-unnecessary type. These types are illustrated in detail below. In a preferred mode of the peeling-off type film unit, at least one image-receiving layer is provided on one support, and a photosensitive element is provided on a support having a light-shielding layer. The coated surface of the photosensitive layer and the coated surface of the mordant layer do not face each other before termination of exposure, but after termination of exposure (for example , during development processing) the coated surface of the photosensitive layer is turned over in an image-forming apparatus to be in contact with the coated surface of the image-receiving layer. After a transferred image is completed on the mordant layer, the photosensitive element is rapidly peeled off from the image-receiving element.
Further, in a preferred mode of the peeling-off-unnecessary type film unit, at least one mordant layer is provided on a transparent support, and a photosensitive element is provided on a transparent support or a support having a light-shielding layer, and the photosensitive layer is superposed on the mordant layer with coated surfaces facing each other.
A pressure-rupturable container containing an alkali treating solution (a treating element) may further be combined with the above-described forms. Above all, in the peeling-off-unnecessary type film unit in which the image-receiving element and the photosensitive element are laminated on one support, this treating element is preferably arranged between the photosensitive element and a cover sheet superposed thereon. In the form in which the photosensitive element and the image-receiving element are separately coated on two supports, respectively, the treating element is preferably arranged between the photosensitive element and the image-receiving element at development processing at the latest. The treating element preferably contains a light-shielding agent (such as carbon black and a dye which varies in color according to pH) and/or a white pigment (such as titanium oxide) according to the form of film units. Further, in the film unit of the color diffusion transfer system, a neutralization timing mechanism comprising a neutralization layer and a neutralization timing layer in combination is preferably incorporated into a cover sheet, an image-receiving element or a photosensitive element.
Each constitutional element which can be used in the photosensitive material according to the present invention will be explained further in detail below.

I. Photosensitive Sheet

A) Support

Any support generally used in a photographic material can be used as the support of the photosensitive sheet in the present invention as far as it is a smooth and transparent support such as cellulose acetate, polystyrene, polyethylene terephthalate or polycarbonate, and preferably provided with an undercoat layer. The support preferably contains a trace amount of a dye or a pigment such as titanium oxide to usually prevent light piping.
The thickness of the support is from 50 to 350 µm, preferably from 70 to 210 µm, and more preferably from 80 to 150 µm.
A curl-balancing layer or the oxygen-shielding layer disclosed in JP-A-56-78833 can be provided on the back side of the support, if desired.

B) Image-Receiving Layer

The dye image-receiving layer for use in the present invention contains a mordant in a hydrophilic colloid. The layer may be a single layer or may be a multilayer structure multilayer-coated with mordants of different mordant abilities. This is disclosed in JP-A-61-252551. Polymer mordants are preferably used as a mordant.
Examples of the polymer mordants include polymers containing a secondary or tertiary amino group, polymers containing a nitrogen-containing heterocyclic ring moiety and polymers containing a quaternary cation, and preferably having a molecular weight of 5,000 or more, and particularly preferably 10,000 or more.
The coating weight of the mordant is generally from 0.5 to 10 g/m², preferably from 1.0 to 5.0 g/m², and particularly preferably from 2 to 4 g/m².
Examples of the hydrophilic colloids for use in the image-receiving layer include gelatin, polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone, but gelatin is preferably used.
The discoloration inhibitors disclosed in JP-B-62-30620, JP-B-62-30621 and JP-A-62-215272 can be incorporated into the image-receiving layer.

C) White Reflective Layer

The white reflective layer forming the white background of a color image usually comprises a white pigment and a hydrophilic binder.
Examples of the white pigments for the white reflective layer include barium sulfate, zinc oxide, barium stearate, silver flakes, silicates, alumina, zirconium oxide, sodium zirconium sulfate, kaolin, mica and titanium dioxide. In addition, non-film-forming polymer particles formed of styrene or the like may be used. They may be used alone or may be used in admixture within the range giving a reflectance to be desired.
Particularly useful white pigment is titanium dioxide.
The whiteness of the white reflective layer varies according to the kind of the pigment, the mixing ratio of the pigment and the binder and the coating weight of the pigment, however, it is desired that the light reflectance be 70% or more. In general, the whiteness increases with an increase in the coating amount of the pigment, however, when the image-forming dye diffuses through this layer, the diffusion of the dye is resisted by the pigment. It is, therefore, desired to select the appropriate coating amount of the pigment.
It is preferred that titanium dioxide be coated in an amount of from 5 to 40 g/m², preferably from 10 to 25 g/m², to obtain a white reflective layer having a light reflectance of from 78 to 85% measured with light having a wavelength of 540 nm.
Titanium dioxide can be selected from various brands commercially available.
In particular, rutile type titanium dioxide is preferably used above all.
Many of the commercially available products are surface treated with alumina, silica, zinc oxide and the like. Titanium dioxide of 5% or more of the surface treating amount is preferred for obtaining a high reflectance. Commercially available titanium dioxide includes, for example, those disclosed in Research Disclosure, No. 15162, as well as Ti-pure R931, the product of E.I. Du Font de Nemours.
The binders suitable for the white reflective layer include alkali-permeable high polymer matrices, for example, gelatin, polyvinyl alcohol, and cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose.
Gelatin is particularly preferably used as the binder for the white reflective layer. The ratio of white pigment/gelatin is from 1/1 to 20/1 (by weight), and preferably from 5/1 to 10/1 (by weight).
It is preferred that the discoloration inhibitors as disclosed in JP-B-62-30620 (the term "JP-B" as used herein means an "examined Japanese patent publication") and JP-B-62-30621 are incorporated into the white reflective layer.

D) Light-Shielding Layer

A light-shielding layer containing a light-shielding agent and a hydrophilic binder is provided between the white reflective layer and the photosensitive layer.
As the light-shielding agent, any material which has a light-shielding function can be used, but carbon black is preferably used. Also, the decomposable dyes disclosed in U.S. Patent 4,615,966 may be used.
As the binder for applying the light-shielding agent, any material can be used so long as it can disperse carbon black, but gelatin is preferably used.
Carbon black raw materials which can be used in the present invention include those produced by any method such as the channel method, the thermal method and the furnace method disclosed, for example, in Donnel Voet, Carbon Black, Marcel Dekker, Inc. (1976). There is no particular limitation on the particle size of carbon black, but the particle size is preferably from 90 to 1,800 Å. The amount of a black pigment to be added as the light-shielding agent may be adjusted according to the sensitivity of the photographic material to be shaded, and the optical density of from 5 to 10 or so is preferred.

E) Photosensitive Layer

In the present invention, the photosensitive layer comprising a silver halide emulsion layer associated with a dye image-forming compound is provided on the above-described light-shielding layer. The constitutional elements thereof are described below.

(1) Dye Image-Forming Compound

Specific examples of the dye image-forming compounds are disclosed in the following literature:

Examples of yellow dyes:

U.S. Patents 3,597,200, 3,309,199, 4,013,633, 4,245,028, 4,156,609, 4,139,383, 4,195,992, 4,148,641, 4,148,643, 4,336,322, JP-A-51-114930, JP-A-56-71072, Research Disclosure, No. 17630 (1978) and ibid., No. 16475 (1977).

Examples of magenta dyes:

U.S. Patents 3,453,107, 3,544,545, 3,932,380, 3,931,144, 3,932,308, 3,954,476, 4,233,237, 4,255,509, 4,250,246, 4,142,891, 4,207,104, 4,287,292, JP-A-52-106727, JP-A-53-23628, JP-A-55-36804, JP-A-56-73057, JP-A-56-71060, JP-A-55-134, JP-A-7-120901, JP-A-8-286343, JP-A-8-286344 and JP-A-8-292537.

Examples of cyan dyes:

U.S. Patents 3,482,972, 3,929,760, 4,013,635, 4,268,625, 4,171,220, 4,242,435, 4,142,891, 4,195,994, 4,147,544, 4,148,642, British Patent 1,551,138, JP-A-54-99431, JP-A-52-8827, JP-A-53-47823, JP-A-53-143323, JP-A-54-99431, JP-A-56-71061, European Patents (EP) 53037, 53040, Research Disclosure, No. 17630 (1978) and ibid., No. 16475 (1977).
A dye image-forming compound which forms a dye by coupling can also be used in the present invention, for example, those disclosed in JP-A-8-286340, JP-A-9-152705, JP-A-10-239793, JP-A-10-186564 and JP-A-10-293388.
A positive type dye image-forming compound can also be used in the present invention. In this case, a negative emulsion is used as a silver halide emulsion. Examples of such dyes are disclosed in JP-A-4-156542, JP-A-4-155332, JP-A-4-172344, JP-A-4-172450, JP-A-4-318844, JP-A-4-356046, JP-A-5-45824, JP-A-5-45825, JP-A-5-53279, JP-A-5-107710, JP-A-5-241302, JP-A-5-107708, JP-A-5-232659, and U.S. Patent 5,192,649.
These compounds can be dispersed according to the method disclosed in JP-A-62-215272, pages 144 to 146. These dispersions may contain the compounds disclosed in JP-A-62-215272, pages 137 to 144. As the specific examples of these dye-forming compounds, the following shown compounds can be exemplified. In the following compounds, Dye represents a dye group, a dye group temporarily shortened in wavelength, or a dye precursor group.

(2) Silver Halide Emulsion

The silver halide emulsions for use in the present invention are internal latent image type direct positive emulsions in which latent images are formed inside silver halide grains.
Examples of the internal latent image type direct positive emulsions include so-called "conversion type" emulsions which are prepared by utilizing the difference in solubility of silver halides and "core/shell type" emulsions in which at least the photosensitive sites of the inner core grains of silver halides doped with metal ions and/or chemically sensitized are covered with outer shells of silver halides. These emulsions are described, for example, in U.S. Patents 2,592,250 and 3,206,313, British Patent 1,027,146, U.S. Patents 3,761,276, 3,935,014, 3,447,927, 2,297,875, 2,563,785, 3,551,662, 4,395,478, West German Patent 2,728,108, and U.S. Patent 4,431,730.
Further, when the internal latent image type direct positive emulsions are used, it is necessary to give surface fogging nuclei using a nucleating agent after imagewise exposure.
The nucleating agents for such a purpose include the hydrazines disclosed in U.S. Patents 2,563,785 and 2,588,982; the hydrazines and the hydrazones disclosed in U.S. Patent 3,227,552; the heterocyclic quaternary salt compounds disclosed in British Patent 1,283,835, JP-A-52-69613, U.S. Patents 3,615,615, 3,719,494, 3,734,738, 4,094,683 and 4,115,122; the sensitizing dyes having substituents with a nucleating function in dye molecules disclosed in U.S. Patent 3,718,470; the thiourea-bonding type acylhydrazine-based compounds disclosed in U.S. Patents 4,030,925, 4,031,127, 4,245,037, 4,255,511, 4,266,013, 4,276,364 and British Patent 2,012,443; and the acylhydrazine based compounds bonded with thioamido rings or heterocyclic groups such as triazole and tetrazole as adsorptive groups disclosed in U.S. Patent 4,080,270, 4,278,748 and British Patent 2,011,391B.
In the present invention, spectral sensitizing dyes can be used in combination with these internal latent image type direct positive emulsions. Specific examples thereof are disclosed in JP-A-59-180550, JP-A-60-140335, Research Disclosure (RD), No. 17029, U.S. Patents 1,846,300, 2,078,233, 2,089,129, 2,165,338, 2,231,658, 2,917,516, 3,352,857, 3,411,916, 2,295,276, 2,481,698, 2,688,545, 2,921,067, 3,282,933, 3,397,060, 3,660,103, 3,335,010, 3,352,680, 3,384,486, 3,623,881, 3,718,470, and 4,025,349.

(3) Constitution of Photosensitive Layer

For the reproduction of natural colors by the subtractive color process, a photosensitive layer is used which comprises at least two, in combination, of the emulsion spectrally sensitized with the above-described spectral sensitizing dye and the above-described dye image-forming compound providing a dye having selective spectral absorption within the same wavelength range. The emulsion and the dye image-forming compound may be either coated one over the other as separate layers, or may be coated as one layer by mixing them. When the dye image-forming substance has absorption in the spectral sensitivity region of the emulsion combined therewith in the coated state, it is preferred that they are coated as separate layers. Further, the emulsion layer may comprise a plurality of emulsion layers having different sensitivities, and an optional layer may be provided between the emulsion layer and the dye image-forming compound layer. For example, color image density can be raised by providing the layer containing the nucleating development accelerator disclosed in JP-A-60-173541 or the bulkhead layer disclosed in JP-B-60-15267, or the sensitivity of the photosensitive elements can be enhanced by providing a reflective layer.
The reflective layer is a layer containing a white pigment and a hydrophilic binder. The white pigment is preferably titanium oxide and the hydrophilic binder is preferably gelatin. The coating weight of titanium oxide is from 0.1 to 8 g/m², and preferably from 0.2 to 4 g/m². Examples of the reflective layers are disclosed in JP-A-60-91354.
In a preferred multilayer structure, a combined unit of blue-sensitive emulsions, a combined unit of green-sensitive emulsions and a combined unit of red-sensitive emulsions are arranged in this order from the exposure side.
Arbitrary layers can be provided between the respective emulsion layer units, if desired. In particular, an interlayer is preferably provided in order to prevent other emulsion layer units from being adversely affected by the development effect of a certain emulsion layer.
An irradiation-preventing layer, an ultraviolet absorbing layer, a protective layer, etc., may be provided in the present invention, according to necessity.

F) Peeling-Off Layer

In the present invention, a peeling-off layer can be provided to be peeled off in any portion of a photosensitive sheet in a unit after processing, as required. Accordingly, this peeling-off layer must be easily peeled off after processing.
Examples of materials which can be used for this purpose are disclosed in JP-A-47-8237, JP-A-59-220727, JP-A-59-229555, JP-A-49-4653, U.S. Patents 3,220,835, 4,359,518, JP-A-49-4334, JP-A-56-65133, JP-A-45-24075, U.S. Patents 3,227,550, 2,759,825, 4,401,746 and 4,366,227. One specific example thereof is a water-soluble (or alkali-soluble) cellulose derivative such as hydroxyethyl cellulose, cellulose acetate phthalate, plasticized methyl cellulose, ethyl cellulose, cellulose nitrate, carboxymethyl cellulose, etc. Other examples include various natural polymers such as alginic acid, pectin and gum arabic. Further, various modified gelatin such as acetylated gelatin and phthalated gelatin can also be used. Still other examples include water-soluble synthetic polymers such as polyvinyl alcohol, polyacrylate, polymethyl methacrylate, polybutyl methacrylate and copolymers thereof.
The peeling-off layer may be a single layer or may comprise a plurality of layers as disclosed in JP-A-59-220727 and JP-A-60-60642.
It is preferred that the color diffusion transfer photographic material according to the present invention is allowed to have a neutralization function between a support and a photosensitive layer, between a support and an image-receiving layer, or on a cover sheet.

G) Support

Any support commonly used in a photographic material can be used as the support of the cover sheet in the present invention as long as it is a smooth and transparent support such as cellulose acetate, polystyrene, polyethylene terephthalate or polycarbonate, and preferably provided with an undercoat layer.
The support preferably contains a trace amount of a dye to prevent light piping.

H) Layer Having Neutralization Function

The layer having a neutralization function for use in the present invention is a layer containing an acidic substance in a sufficient amount to neutralize the alkali incorporated from the processing composition. The layer may have a multilayer structure comprising layers such as a neutralization speed controlling layer (i.e., a timing layer) and an adhesion-enhancing layer, if desired. Preferred examples of such acidic substances include substances containing an acidic group having a pKa of 9 or less (or a precursor group giving such an acidic group by hydrolysis). More preferably, the acidic substances include higher fatty acids such as the oleic acid as disclosed in U.S. Patent 2,983,606; the polymers of acrylic acid, methacrylic acid or maleic acid, partial esters thereof or acid anhydrides thereof disclosed in U.S. Patent 3,362,819; the copolymers of acrylic acid and acrylates disclosed in French Patent 2,290,699; and the latex type acidic polymers disclosed in U.S. Patent 4,139,383 and Research Disclosure, No. 16102 (1977).
In addition, the acidic substances also include those disclosed in U.S. Patent 4,088,493, JP-A-52-153739, JP-A-53-1023, JP-A-53-4540, JP-A-53-4541 and JP-A-53-4542.
Specific examples of the acidic polymers include copolymers of maleic anhydride and vinyl monomers such as ethylene, vinyl acetate and vinyl methyl ether, n-butyl ester thereof, copolymers of butyl acrylate and acrylic acid, cellulose acetate, and hydrogen phthalate.
The above-described acidic polymers can be used by mixture with hydrophilic polymers. Examples of such polymers include polyacrylamide, polymethylpyrrolidone, polyvinyl alcohol (including partially saponified polyvinyl alcohol), carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and polymethyl vinyl ether. Polyvinyl alcohol is preferred above all.
The above-described acidic polymers may be mixed with polymers other than the hydrophilic polymers, e.g., cellulose acetate.
The coating amount of the acidic polymer is adjusted based on the amount of the alkali developed on the photosensitive element. The equivalent ratio of the acidic polymer to the alkali per unit area is preferably from 0.9 to 2.0. If the amount of the acidic polymer is too small, the hue of a transfer dye changes or stains are generated on a white background part. If the amount is too large, troubles such as a change in hue and a decrease in light fastness arise. More preferably, the equivalent ratio thereof is from 1.0 to 1.3. Too large or too small an amount of the hydrophilic polymer to be mixed also deteriorates the quality of a photograph. The weight ratio of the hydrophilic polymer to the acidic polymer is from 0.1 to 10, and preferably from 0.3 to 3.0.
Additives can be incorporated into the layer having the neutralization function according to the present invention for various purposes. For example, a hardening agent known in the art can be added to this layer to harden the layer, and a multivalent hydroxyl compound such as polyethylene glycol, polypropylene glycol or glycerol can be added to this layer to improve the brittleness of the film. In addition, an antioxidant, a brightening agent, a development inhibitor or a precursor thereof can also be added, if desired.
Useful polymers for the timing layer which is used in combination with the neutralization layer include polymers reducing alkali permeability such as gelatin, polyvinyl alcohol, partially acetalized products of polyvinyl alcohol, cellulose acetate and partially hydrolyzed polyvinyl acetate; latex polymers elevating the activation energy of alkali permeation which are produced by copolymerizing a small amount of hydrophilic comonomers such as an acrylic acid monomer; and polymers having lactone rings.
Particularly useful polymers for the timing layers include the cellulose acetate disclosed in JP-A-54-136328, U.S. Patents 4,267,262, 4,009,030 and 4,029,849; the latex polymers produced by copolymerizing a small amount of hydrophilic comonomers such as acrylic acid disclosed in JP-A-54-128335, JP-A-56-69629, JP-A-57-6843, U.S. Patents 4,056,394, 4,061,496, 4,199,362, 4,250,243, 4,256,827 and 4,268,604; the polymers having lactone rings disclosed in U.S. Patent 4,229,516; and the polymers disclosed in JP-A-56-25735, JP-A-56-97346, JP-A-57-6842, EP-A-31957, EP-A-37724 and EP-A-48412.
In addition, the polymers disclosed in the following literature can also be used, for example, U.S. Patents 3,421,893, 3,455,686, 3,575,701, 3,778,265, 3,785,815, 3,847,615, 4,088,493, 4,123,275, 4,148,653, 4,201,587, 4,288,523, 4,297,431, West German Patent Application (OLS) Nos. 1,622,936, 2,162,277, and Research Disclosure, No. 15162, Vol. 151 (1976).
The timing layers using these polymers can be used as a single layer or two or more layers in combination.
Further, for example, the development inhibitors and/or precursors thereof disclosed in U.S. Patent 4,009,029, West German Patent Application (OLS) Nos. 2,913,164 and 3,014,672, JP-A-54-155837 and JP-A-55-138745, the hydroquinone precursors disclosed in U.S. Patent 4,201,578, and other useful photographic additives or precursors thereof can be incorporated into the timing layers formed of these polymers.
Moreover, it is effective for the layer having the neutralization function to be provided with an auxiliary neutralization layer for the purpose of decreasing a change in transfer density with the lapse of time after processing as disclosed in JP-A-63-168648 and JP-A-63-168649.

I) Others

In addition to the layer having the neutralization function, the cover sheet may have auxiliary layers such as a backing layer, a protective layer, and a filter dye layer.
The backing layer is provided to control curling or to impart a slipperiness. A filter dye may be added to this layer.
The protective layer is used primarily to prevent adhesion to a cover sheet back surface and adhesion to the protective layer of the photographic material when the cover sheet is superposed on the photographic material.
The cover sheet can contain a dye to adjust the sensitivity of the photosensitive layer. A filter dye may be directly added to the support of the cover sheet, the layer having the neutralization function, the backing layer, the protective layer, or the dye capturing mordant layer, or a single layer to contain the filter dye may be formed.

II. Alkali Treating Composition

The alkali treating composition for use in the present invention is uniformly developed on the photosensitive elements after exposure thereof, is provided on the back surface of the support or on the side opposite to the treating solution for the photosensitive layer to make a pair with the light-shielding layer, to thereby completely shield the photosensitive layer from external light, and concurrently performs the development of the photosensitive layer with the components contained therein. For this purpose, the composition contains an alkali, a thickener, a light-shielding agent and a developing agent, and further contains a development accelerator or a development inhibitor for controlling development, and an antioxidant for preventing the developing agent from deteriorating. The light-shielding agent is necessarily contained in the composition for the purpose of shading.
The alkali is a compound which can adjust the pH of the solution to 12 to 14, and examples thereof include hydroxides of alkali metals (e.g., sodium hydroxide, potassium hydroxide, lithium hydroxide), phosphates of alkali metals (e.g., potassium phosphate) , guanidines and hydroxides of quaternary amines (e.g., tetramethylammonium hydroxide). Above all, potassium hydroxide and sodium hydroxide are preferred.
The thickener is necessary to develop the treating solution uniformly and to maintain adhesion between the photosensitive layer and the cover sheet. For example, polyvinyl alcohol, hydroxyethyl cellulose and alkaline metal salts of carboxymethyl cellulose are used, and hydroxyethyl cellulose and sodium carboxymethyl cellulose are preferably used.
As the light-shielding agent, either a dye or a pigment or a combination thereof can be used provided it does not generate stains by diffusing to the dye image-receiving layer. Typical examples thereof include carbon black.
Any developing agent can be used as long as it cross oxidizes the dye image-forming compound and does not substantially generate stains when oxidized. Such a developing agent can be used alone or in combination of two or more, and may be used in the form of precursors. The developing agent may be contained in appropriate layers of the photosensitive elements or in the alkali treating solution. Specific examples thereof include aminophenols and pyrazolidinones. Of these, pyrazolidinones are particularly preferred because less stain is generated.
For example, 1-phenyl-3-pyrazolidinone, 1-p-tolyl-4,4-dihydroxymethyl-3-pyrazolidinone, 1-(3'-methylphenyl)-4-methyl-4-hydroxymethyl-3-pyrazolidinone, 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone and 1-p-tolyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone can be enumerated.
Any of the photosensitive sheet, the cover sheet and the alkali treating composition can contain the development accelerators disclosed on pages 72 to 91, the hardening agents disclosed on pages 146 to 155, the surfactants disclosed on pages 201 to 210, the fluorine compounds disclosed on pages 210 to 222, the thickeners disclosed on pages 225 to 227, the antistatic agents disclosed on pages 227 to 230, the polymer latexes disclosed on pages 230 to 239, the matting agents disclosed on page 240, of JP-A-62-215272. Any of them can contain tertiary amine latexes disclosed in JP-A-6-273907, JP-A-7-134386, JP-A-7-175193 and JP-A-7-287372.
These alkali solution compositions are preferably developed to the photographic materials in extended thickness (the amount of the treating solution per m² after transfer of the treating solution) of from 20 to 200 µm.
When the photographic materials are processed, the processing temperature is preferably from 0 to 50°C, and more preferably from 0 to 40°C.
The heat-developable color photographic materials in which the dye image-forming compounds according to the present invention are used (dye-fixing elements), applicable methods of exposure and heating, and apparatuses are disclosed in detail in paragraphs from 0128 to 0159 of JP-A-7-219180.
The present invention will be specifically described with reference to the examples but the present invention is not limited thereto.

EXAMPLE 1

The preparing methods of silver halide emulsions are described in the first place.
Eight kinds of silver halide emulsion grains (Emulsion-A to Emulsion-F) and Emulsion-T and Emulsion-U were prepared according to the following preparing methods of emulsion grains.

Preparation of Emulsion-A (octahedral internal latent image type direct positive emulsion)

Into 1,000 ml of an aqueous gelatin solution containing 0.05 M of potassium bromide, 1 g of 3,6-dithia-1,8-octanediol, 0.034 mg of lead acetate, and 60 g of deionized gelatin having a Ca content of 100 ppm or less were added 300 ml of 0.4 M of an aqueous silver nitrate solution and 0.4 M of an aqueous potassium bromide solution by a controlled double jet method over 40 minutes by controlling the addition rate of the aqueous potassium bromide solution so that the pBr became 1.60 with maintaining the temperature at 75°C.
After completion of the addition, octahedral silver bromide crystals (hereinafter referred to as "core grains") of uniform grain size having average grain size (equivalent-sphere diameter) of about 0.7 µm were formed.
Chemical sensitization of core grains was performed under the following conditions.
1. Tank: The metal surface was finished by Teflon coating with fluorine resin FEP (developed by E.I. Du Pont de Nemours) in a thickness of 120 µm and the bottom was hemispheric shape.
2. Stirring blades: A monolithic propeller type and the metal surface was finished by Teflon coating.
To the above-prepared solution of Emulsion-A were added 3 ml of an aqueous solution prepared by dissolving 1 mg of sodium thiosulfate, 90 mg of potassium tetrachloroaurate and 1.2 g of potassium bromide in 1,000 ml of water, and chemical sensitization treatment was performed by heating the emulsion solution at 75°C for 80 minutes. To the emulsion solution thus chemically sensitized was added 0.15 M of potassium bromide and then 670 ml of 0.9 M of an aqueous silver nitrate solution and 0.9 M of an aqueous potassium bromide solution were added thereto by a controlled double jet method over 70 minutes by controlling the addition rate of the aqueous potassium bromide solution so that the pBr became 1.30 with maintaining the temperature at 75°C in the same manner as in the preparation of core grains.
The emulsion was washed with water in an ordinary flocculation method, and the above gelatin, 2-phenoxyethanol, and p-hydroxymethylbenzoate were added, whereby octahedral silver bromide crystals (hereinafter referred to as "internal latent image type core/shell grains") of uniform grain size having average grain size (equivalent-sphere diameter) of about 1.2 µm were obtained.
Subsequently, 3 ml of an aqueous solution prepared by dissolving 100 mg of sodium thiosulfate and 40 mg of sodium tetraborate in 1,000 ml of water was added to the internal latent image type core/shell emulsion, then 14 mg of poly(N-vinylpyrrolidone) were added and the mixed solution was ripened by heating at 60°C. Thereafter, 0.005 M of potassium bromide was added to the above solution to thereby obtain an octahedral internal latent image type direct positive emulsion.

Preparation of Emulsion-B to Emulsion-F (octahedral internal latent image type direct positive emulsion)

Emulsion-B to Emulsion-F were prepared in the same manner as in the preparation of Emulsion-A except that the addition time of the aqueous silver nitrate solution and the aqueous potassium bromide solution was changed and the amounts of the compounds added were changed. As a result, octahedral internal latent image type direct positive emulsions of uniform grain size each having average grain size shown in Table 1 (equivalent-sphere diameter) were obtained.

Emulsion Name Average Grain Size (µm)

B 0.93

C 1.20

D 0.94

E 0.74

F 0.66

Preparation of Emulsion-T (hexagonal tabular internal latent image type direct positive emulsion)

Into 1.2 liters of an aqueous gelatin solution containing 0.05 M of potassium bromide and 0.7 wt% of gelatin having an average molecular weight of 100,000 or less were simultaneously added 33 ml of 1.4 M of an aqueous silver nitrate solution containing the above gelatin and 33 ml of 2 M of an aqueous potassium bromide solution by a double jet method with vigorously stirring for 1 minute. During the stirring, the aqueous gelatin solution was maintained at 30°C. Further, after 300 ml of a gelatin solution containing 10 wt% of deionized gelatin having a Ca content of 100 ppm or less were added thereto, the temperature was increased to 75°C.
Subsequently, 40 ml of 0.9 M of an aqueous silver nitrate solution were added to the above solution over 3 minutes, then a 25 wt% aqueous ammonia solution was further added and ripening was performed at 75°C. After completion of the ripening, ammonia was neutralized, and 5 mg of lead acetate (as an aqueous solution) was added. Thereafter, 1 M of an aqueous silver nitrate solution and 1 M of an aqueous potassium bromide solution were added thereto by a double jet method at an accelerated flow rate (the final flow rate was six times of the initial flow rate) with maintaining the pBr at 2.5 (the amount of the aqueous silver nitrate solution used was 500 ml).
The thus-formed grains (hereinafter referred to as "core grains") was washed with water in an ordinary flocculation method, and gelatin, 2-phenoxyethanol, and p-hydroxymethylbenzoate were added, whereby 750 g of hexagonal tabular core grains were obtained.
The thus-obtained hexagonal tabular core grains had an average equivalent-circle diameter of the projected area of 0.9 µm and an average thickness of 0.20 µm, and 95% of all the projected area was occupied by hexagonal tabular grains.
Chemical sensitization of core grains was performed under the following conditions.
1. Tank: The metal surface was finished by Teflon coating with fluorine resin FEP (developed by Du Pont) in a thickness of 120 µm and the bottom was hemispheric shape.
2. Stirring blades: A monolithic propeller type and the metal surface was finished by Teflon coating.
To 200 g of the above hexagonal tabular core emulsion were added 1,300 ml of water, 0.11 M of potassium bromide and 40 g of deionized gelatin, and the temperature was raised to 75°C. Then, 2.4 ml of an aqueous solution prepared by dissolving 0.3 g of 3,6-dithia-1,8-octanediol, 10 mg of sodium benzenethiosulfate, 90 mg of potassium tetrachloroaurate and 1.2 g of potassium bromide in 1,000 ml of water, and 15 mg of lead acetate (as an aqueous solution) were added to the above emulsion, and chemical sensitization was performed by heating at 75°C for 180 minutes. To the core grains thus chemically sensitized were added, in the same manner as in the preparation of core grains, 2 M of an aqueous silver nitrate solution and 2.5 M of an aqueous potassium bromide solution by a double jet method by controlling the addition rate of the aqueous potassium bromide solution so that the pBr became 2.2 at an accelerated flow rate (the final flow rate was three times of the initial flow rate) (the amount of the aqueous silver nitrate solution used was 810 ml).
After 0.3 M of potassium bromide was added, the emulsion was washed with water in an ordinary flocculation method and gelatin was added thereto. Thus, a hexagonal tabular internal latent image type core/shell emulsion was obtained. The thus-obtained hexagonal tabular grains had an average equivalent-circle diameter of the projected area of 2.0 µm and an average thickness of 0.38 µm, an average volume size of 1.3 (µm)³ and 88% of all the projected area was occupied by hexagonal tabular grains.
Subsequently, 15 ml of an aqueous solution prepared by dissolving 100 mg of sodium thiosulfate and 40 mg of sodium tetraborate in 1,000 ml of water were added to the hexagonal tabular internal latent image type core/shell emulsion, and further 20 mg of poly(N-vinylpyrrolidone) were added and grain surfaces of the emulsion were chemically sensitized by heating at 70°C for 100 minutes. Thus, a hexagonal tabular internal latent image type direct positive emulsion was prepared.

Preparation of Emulsion-U (hexagonal tabular internal latent image type direct positive emulsion)

At the time of forming outer shell of Emulsion-T, 0.15 mol% of iodide was uniformly added to thereby further increase the amount of outer shell. The thus-obtained hexagonal tabular grains had an average equivalent-circle diameter of the projected area of 2.5 µm and an average grain thickness of 0.45 µm, an average volume size of 1.7 (µm)³ and 88% of all the projected area was occupied by hexagonal tabular grains.
After AgI fine grain Emulsion-X corresponding to 0.04 mol% of the silver amount required in the grain formation at the beginning of chemical sensitization of the shell part of the hexagonal tabular internal latent image type core/shell emulsion was added, chemical sensitization of the shell part was performed in the same manner as in the chemical sensitization of Emulsion-T, whereby a hexagonal tabular internal latent image type direct positive emulsion was obtained.

Preparation of Emulsion-X (AgI fine grain emulsion)

To a solution prepared by adding 0.5 g of potassium iodide and 26 g of gelatin to water and maintained at 35°C were added 80 ml of an aqueous silver nitrate solution containing 40 g of silver nitrate and 80 ml of an aqueous potassium iodide solution containing 39 g of potassium iodide over 5 minutes. The initial addition rates of the aqueous silver nitrate solution and the aqueous potassium iodide solution were respectively 8 ml/min and the addition rates were accelerated linearly so that the addition of 80 ml was completed in 5 minutes.
After the grains had been formed, soluble salts were removed by a precipitation method at 35°C. Then, the temperature of the emulsion was raised to 40°C, 10.5 g of gelatin and 2.56 g of phenoxyethanol were added thereto and the pH was adjusted to 6.8 with sodium hydroxide. Thus, monodispersed AgI fine grains having an average diameter of 0.015 µm were obtained. The finished amount of the emulsion obtained was 730 g.

Comparative photosensitive element Sample No. 101 having the constitution shown in the following Table 2 was prepared by using Emulsions-A to F, T and U. The kind, type of dispersion, addition temperature and amount of sensitizing dyes added at the time of completion of chemical sensitization of the shell part are shown in the following Table 3.

Constitution of Comparative Photosensitive Element No. 101
Layer No.	Layer Name	Additive	Coating Amount
			(g/m²)
22nd Layer	Protective Layer	Matting Agent (1)	0.15
		Gelatin	0.25
		Surfactant (1)	5.3 × 10^-3
		Surfactant (2)	4.1 × 10^-3
		Surfactant (3)	3.9 × 10^-3
		Additive (1)	8.0 × 10^-3
		Additive (5)	0.009
21st Layer	Ultraviolet Absorbing Layer	Ultraviolet Absorbing Agent (1)	0.09
		Ultraviolet Absorbing Agent (2)	0.05
		Ultraviolet Absorbing Agent (3)	0.01
		Surfactant (3)	0.013
		Surfactant (4)	0.019
		Additive (1)	8.0 × 10^-3
		Additive (5)	0.023
		Hardening Agent (1)	0.050
		Hardening Agent (2)	0.017
		Gelatin	0.52
20th Layer	Blue-Sensitive Layer (high speed)	Internal Latent Image Type Direct Positive Emulsion: U	0.38
	(in terms
		of silver)
	Nucleating Agent (1)	2.9 × 10^-6
		Additive (3)	4.0 × 10^-3
		Additive (4)	0.013
		Additive (5)	3.8 × 10^-3
		Additive (1)	9.0 × 10^-3
		Surfactant (5)	9.0 × 10^-3
		Gelatin	0.42
19th Layer	Blue-Sensitive Layer (low speed)	Internal Latent Image Type Direct Positive Emulsion: A	0.07
	(in terms of silver)
	Internal Latent Image Type Direct Positive Emulsion: B	0.10
		(in terms of silver)
		Nucleating Agent (1)	2.5 × 10^-6
		Additive (3)	0.022
		Additive (5)	9.0 × 10^-3
		Additive (1)	0.013
		Surfactant (5)	9.0 10^-3
		Gelatin	0.35
18th Layer	White Reflective Layer	Titanium Dioxide	0.30
		Additive (1)	9.0 × 10^-3
		Surfactant (1)	7.2 × 10^-5
		Additive (5)	0.011
		Additive (8)	2.8 × 10^-3
		Gelatin	0.37
17th Layer	Yellow Color Material Layer	Yellow Dye-Releasing Compound (1)	0.62
		High Boiling Point Organic	0.27
		Solvent (1)
		Additive (6)	0.18
		Additive (7)	0.09
		Surfactant (4)	0.062
		Surfactant (5)	0.030
		Additive (9)	0.031
		Additive (1)	6.0 × 10^-3
		Gelatin	0.87
16th Layer	Interlayer	Additive (10)	0.013
		Surfactant (1)	4.0 × 10^-4
		Additive (1)	7.0 × 10^-3
		Gelatin	0.42
15th Layer	Color Mixing Preventing Layer	Hydroquinone (A)	1.13
15th Layer	Polymethyl Methacrylate	1.22
		Surfactant (5)	0.045
		Additive (1)	3.8 × 10^-3
		Additive (12)	0.61
		Gelatin	1.22
14th Layer	Green-Sensitive Layer (high speed)	Internal Latent Image Type Direct Positive Emulsion: T	0.69
	(in terms of silver)
	Nucleating Agent (1)	2.2 × 10^-6
		Additive (3)	0.12
		Additive (5)	0.014
		Additive (1)	3.0 × 10^-3
		High Boiling Point Organic Solvent (2)	0.07
		Surfactant (5)	0.06
		Gelatin	0.97
13th Layer	Green-Sensitive Layer (low speed)	Internal Latent Image Type Direct Positive Emulsion: C	0.11
13th Layer	(in terms of silver)
	Internal Latent Image Type Direct Positive Emulsion: D	0.08
		(in terms of silver)
		Nucleating Agent (1)	2.7 × 10^-6
		Additive (3)	0.011
		Additive (4)	0.033
		Additive (5)	1.5 × 10^-3
		Additive (1)	0.010
		Surfactant (5)	0.024
		Gelatin	0.26
12th Layer	Interlayer	Additive (1)	0.014
		Surfactant (1)	0.038
		Surfactant (3)	4.0 × 10^-3
		Additive (5)	0.014
		Gelatin	0.33
11th Layer	Magenta Color Material Layer	Magenta Dye-Releasing Compound (1)	0.56
		High Boiling Point Organic Solvent (1)	0.18
		Additive (13)	9.3 × 10^-4
		Additive (5)	0.02
		Surfactant (4)	0.04
		Additive (14)	0.02
		Additive (1)	7.0 × 10^-3
		Gelatin	0.45
10th Layer	Interlayer	Additive (10)	0.014
		Surfactant (1)	3.0 × 10^-4
		Additive (1)	9.0 × 10^-3
		Gelatin	0.36
9th Layer	Color Mixing Preventing Layer	Hydroquinone (A)	0.90
		Polymethyl Methacrylate	0.97
		Surfactant (5)	0.038
		Additive (1)	2.0 × 10^-3
		Additive (12)	0.49
		Gelatin	0.97
8th Layer	Red-Sensitive Layer (high speed)	Internal Latent Image Type Direct Positive Emulsion: T	0.33
8th Layer	(in terms of silver)
		Nucleating Agent (1)	6.1 × 10^-6
		Additive (3)	0.04
		Additive (5)	0.01
		Additive (1)	1.0 × 10^-3
		High Boiling Point Organic	0.04
		Solvent (2)
		Surfactant (5)	0.02
		Gelatin	0.33
7th Layer	Red-Sensitive Layer (low speed)	Internal Latent Image Type Direct Positive Emulsion: E	0.10
7th Layer	(in terms of silver)
		Internal Latent Image Type Direct Positive Emulsion: F	0.11
		(in terms of silver)
		Nucleating Agent (1)	2.5 × 10^-5
		Additive (3)	0.047
		Additive (5)	0.016
		Additive (1)	8.0 × 10^-3
		Surfactant (5)	0.02
		Gelatin	0.57
6th Layer	White Reflective Layer	Titanium Dioxide	1.87
		Additive (1)	7.0 × 10^-3
		Surfactant (1)	4.0 × 10^-4
		Additive (5)	0.02
		Additive (8)	0.015
		Gelatin	0.73
5th Layer	Cyan Color Material Layer	Cyan Dye-Releasing Compound (1)	0.25
		Cyan Dye-Releasing Compound	0.14
		(2)
		High Boiling Point Organic	0.05
		Solvent (1)
		Additive (3)	0.06
		Additive (5)	0.01
		Surfactant (4)	0.05
		Additive (9)	0.05
		Additive (1)	4.0 × 10^-3
		Hardening Agent (3)	0.014
		Gelatin	0.40
4th Layer	Light-Shielding Layer	Carbon Black	1.50
		Surfactant (1)	0.08
		Additive (1)	0.06
		Additive (5)	0.06
		Additive (14)	0.15
		Gelatin	1.43
3rd Layer	Interlayer	Surfactant (1)	6.0 × 10^-4
		Additive (1)	9.0 × 10^-3
		Additive (5)	0.013
		Gelatin	0.29
2nd Layer	White Reflective Layer	Titanium Dioxide	19.8
		Additive (15)	0.378
		Additive (16)	0.094
		Surfactant (6)	0.019
		Additive (8)	0.16
		Hardening Agent (1)	0.02
		Hardening Agent (2)	0.007
		Gelatin	2.45
1st Layer	Image-receiving Layer	Polymer Mordant (1)	2.22
		Additive (17)	0.26
		Surfactant (7)	0.04
		Additive (5)	0.11
		Hardening Agent (1)	0.03
		Hardening Agent (2)	0.01
		Gelatin	3.25
	Support (polyethylene terephthalate which contained titanium dioxide to prevent light piping and provided with an undercoat layer, 90 µm)
Backing Layer	Curling Controlling Layer	Ultraviolet Absorbing Agent (4)	0.40
		Ultraviolet Absorbing Agent (5)	0.10
		Diacetyl Cellulose (acetylation degree: 51%)	4.20
		Additive (18)	0.25
		Barium Stearate	0.11
		Hardening Agent (4)	0.50

Sensitizing Dye (1)

Molecular weight: 728.77
Molecular formula: C₂₅H₂₆Cl₂N₂O₆S₄·C₅H₅N₁

Sensitizing Dye (3)

Molecular weight: 686.24
Molecular formula: C₃₀H₃₁Cl₁N₂O₇S₃·Na₁

Sensitizing Dye (2)

Molecular weight: 782.09
Molecular formula: C₃₃H₃₂N₂O₆S₄·C₆H₁₅N₁

Sensitizing Dye (7)

Molecular weight: 751.89
Molecular formula: C₃₅H₃₂N₂O₈S₂·C₅H₅N₁

Sensitizing Dye (4)

Molecular weight: 707.96
Molecular formula: C₃₃H₃₆N₂O₇S₃·K₁

Sensitizing Dye (6)

Molecular weight: 742.57
Molecular formula: C₃₀H₂₈Cl₂F₇N₅O₃S₁

Sensitizing Dye (9)

Molecular weight: 707.96
Molecular formula: C₂₆H₂₆N₂O₇S₄·C₆H₅N₁

Sensitizing Dye (5)

Molecular weight: 724.83
Molecular formula: C₂₃H₂₄Cl₂N₂O₆S₄·C₆H₁₅N₁

Sensitizing Dye (8)

Molecular weight: 752.00
Molecular formula: C₃₂H₃₀N₂O₇S₃·C₆H₁₅N₁

Yellow Dye-Releasing Compound (1)

Magenta Dye-Releasing Compound (1)

Cyan Dye-Releasing Compound (1)

Cyan Dye-Releasing Compound (2)

Additive (1)

Additive (3)

Additive (4)

Additive (5)

Additive (6)

Additive (7)

Additive (8)

Carboxymethyl Cellulose (CMS CELLOGEN 6A, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

Additive (9)

Polyvinyl Alcohol (PVA-220E) (polymerization degree: about 2,000, saponification degree: 88%)

Additive (10)

Additive (12)

Additive (13)

Additive (14)

Additive (15)

Additive (16)

Additive (17)

Additive (18)

Matting Agent (1)

Polymethyl Methacrylate Spherical Latex (average particle size: 3 µm)

Surfactant (1)

Surfactant (2)

Surfactant (3)

Surfactant (4)

Surfactant (5)

Surfactant (6)

Surfactant (7)

Ultraviolet Absorbing Agent (1)

Ultraviolet Absorbing Agent (2)

Ultraviolet Absorbing Agent (3)

High Boiling Point Organic Solvent (1)

High Boiling Point Organic Solvent (2)

Ultraviolet Absorbing Agent (4)

Ultraviolet Absorbing Agent (5)

Hardening Agent (1)

CH₂=CHSO₂CH₂CONH(CH₂)₂NHCOCH₂SO₂CH=CH₂

Hardening Agent (2)

CH₂= CHSO₂CH₂CONH(CH₂)₃NHCOCH₂SO₂CH=CH₂

Hardening Agent (3)

Hardening Agent (4)

Nucleating Agent (1)

Polymer Mordant (1)

Hydroquinone (A)

Preparation of Cover Sheet

A cover sheet was prepared by coating the layers on a transparent support having a thickness of 75 µm. The layer constitution is shown in Table 4.

Layer Constitution of Cover Sheet
Layer No.	Layer Name	Additive	Coating Amount
3rd Layer	Temperature Compensating Layer	Temperature Compensating Polymer (1)	(g/m²) 0.30
		Temperature Compensating Polymer (2)	0.80
		Surfactant (8)	0.005
2nd Layer	Alkali Barrier Layer	Cellulose Acetate (acetylation degree: 51%)	4.30
		Additive (19)	0.20
		Additive (20)	0.20
		Hardening Agent (2)	0.40
1st Layer	Neutralization Layer	Acidic Polymer (1)	10.40
		Cellulose Acetate (acetylation degree: 45%)	0.70
		Hardening Agent (5)	0.10
	Support (polyethylene terephthalate which contained Additive (21) to prevent light piping and was undercoated with gelatin, 75 µm)
Backing Layer	Curling Controlling Layer	Cellulose Acetate (acetylation degree: 55%)	9.10
		Silica (average particle size: from 3 to 4 µm)	0.04

Chemical structural formulae of the compounds which were used in the cover sheet are shown below.

Surfactant (8)

a/b = 6/4 (by weight)
Mw: from 30,000 to 50,000

Additive (19)

Additive (20)

Hardening Agent (5)

Additive (21)

Temperature Compensating Polymer (1)

a/b/c = 66.1/5.5/28.4 (by weight)

Temperature Compensating Polymer (2)

a/b/c = 66.1/5.5/28.4 (by weight)

Acidic Polymer (1)

a/b/c = 20/76/4 (by weight)

The formulation of the alkali treating composition is shown below.

Silver Nitrate	0.10 g
Carbon Black (manufactured by Dainichi Seika Co., Ltd.)	160 g
Additive (22)	8.60 g
Carboxymethyl Cellulose Sodium Salt	58.0 g
Benzyl Alcohol	2.50 g
Additive (23)	2.10 g
Potassium Sulfite (anhydrous)	1.90 g
5-Methylbenzotriazole	2.50 g
1-p-Tolyl-4-hydroxymethyl-4-methyl-3-pyrazolidone	7.00 g
1-Phenyl-4-hydroxymethyl-4-methyl-3-pyrazolidone	10.0 g
Potassium Hydroxide	56.0 g
Aluminum Nitrate	0.60 g
Zinc Nitrate	0.60 g
Additive (24)	6.60 g
Additive (14)	1.80 g
1,2-Benzisothiazolin-3-one	0.003 g

Additive (22)

Additive (23)

Additive (24)

Photosensitive Element Nos. 102 to 115 were prepared in the same manner as the preparation of Photosensitive Element No. 101 except that the compounds shown in Table 5 were added to the high speed blue-sensitive layer, high speed green-sensitive layer, and high speed red-sensitive layer, respectively. The addition amount of each compound is also shown in Table 5.

Sample No.	Compound No.	Addition Amount (mmol/m²)	Remarks
		High Speed Blue-Sensitive Layer	High Speed Green-Sensitive Layer	High Speed Red-Sensitive Layer
101	-	-	-	-	Comparison
102	I-36	0.131	0.217	0.152	Comparison
103	I-36	0.0524	0.0868	0.0608	Comparison
104	II-3	0.0786	0.130	0.0912	Comparison
105	III-1	0.0786	0.130	0.0912	Comparison
106	IV-47	0.0786	0.130	0.0912	Comparison
107	IV-53	0.0786	0.130	0.0912	Comparison
108	I-36	0.0524	0.0868	0.0608	Invention
II-3	0.0786	0.130	0.0912
109	I-36	0.0524	0.0868	0.0608	Invention
III-1	0.0786	0.130	0.0912
110	I-36	0.0524	0.0868	0.0608	Invention
IV-47	0.0786	0.130	0.0912
111	I-36	0.0524	0.0868	0.0608	Invention
IV-2	0.0786	0.130	0.0912
112	I-33	0.0524	0.0868	0.0608	Invention
IV-53	0.0786	0.130	0.0912
113	I-33	0.0524	0.0868	0.0608	Invention
IV-2	0.0786	0.130	0.0912
114	I-36	0.0524	0.0868	0.0608	Invention
II-4	0.0786	0.130	0.0912
115	I-36	0.0524	0.0868	0.0608	Invention
III-10	0.0786	0.130	0.0912

Each of the above-prepared Photosensitive Element Nos. 101 to 115 was exposed through a gray continuous wedge from the emulsion layer side, then superposed on the above-prepared cover sheet, and the alkali treating composition was developed between both materials by means of a pressure roller in a thickness of 62 µm. After treatment at 25°C for 2 hours, transfer density was measured with a color densitometer and the maximum density and the minimum density of each of yellow, magenta and cyan were evaluated. Further, the time after treatment until image appearance was measured.

The results obtained are shown in Table 6.

Sample No.	Maximum Image Density	Minimum Image Density	Image Appearance Time (sec)
	Yellow	Magenta	Cyan	Yellow	Magenta	Cyan
101	1.51	1.62	2.10	0.203	0.205	0.233	43
102	1.81	2.05	2.36	0.195	0.193	0.217	40
103	1.85	2.06	2.40	0.197	0.197	0.220	36
104	1.86	2.00	2.43	0.210	0.214	0.239	33
105	1.83	2.03	2.44	0.211	0.210	0.237	34
106	1.76	2.10	2.33	0.209	0.214	0.240	33
107	1.84	2.03	2.34	0.210	0.214	0.239	32
108	1.86	2.07	2.40	0.191	0.189	0.212	32
109	1.87	2.11	2.41	0.290	0.190	0.212	32
110	1.97	2.25	2.49	0.186	0.186	0.208	28
111	1.99	2.24	2.50	0.185	0.185	0.207	28
112	1.96	2.27	2.51	0.186	0.186	0.208	27
113	1.95	2.26	2.50	0.185	0.186	0.207	27
114	1.89	2.11	2.40	0.189	0.190	0.211	32
115	1.88	2.13	2.41	0.190	0.189	0.211	32

As is apparent from the comparison of Sample Nos. 108 to 115 with Sample Nos. 101 to 107, the image-appearance time is unexpectedly short and an image having low Dmin and high Dmax can be obtained when the compounds according to the present invention are used in combination as compared with the case where the compound is used alone.

EXAMPLE 2

Also when experiments were performed in the same manner as in Example 1 except that the alkali treating composition was developed in a thickness of 49 µm, it was found that the image-appearance time was short and an image having low Dmin and high Dmax could be obtained similar to Example 1 due to the combination of the compounds according to the present invention.

EXAMPLE 3

A transparent polyethylene terephthalate film support having a thickness of 100 µm was coated with the following each layer to prepare a photosensitive element Sample No. 301.

Backing Layer Side:

(a) a light-shielding layer containing 6.0 g/m² of carbon black and 2.0 g/m² of gelatin,
(b) a protective layer containing 0.5 g/m² of gelatin,

Emulsion Layer Side:

(1) a layer containing 3.7 g/m² of titanium dioxide and 0.5 g/m² of gelatin,
(2) a color material layer containing 0.46 g/m² of the following cyan dye-releasing redox compound, 0.07 g/m² of tricyclohexyl phosphate, 0.05 g/m² of the following Auxiliary Dispersant (A), 0.06 g/m² of the following Auxiliary Dispersant (B) , and 0.5 g/m² of gelatin,

Cyan Dye-Releasing Redox Compound

Auxiliary Dispersant (A)

Auxiliary Dispersant (B)

x/y = 12/88 (molecular weight: 100,000)
(3) a layer containing 0.5 g/m² of gelatin,
(4) a red-sensitive emulsion layer containing 0.11 g/m² in terms of silver of a red-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0. 65 µm), 0.3 g/m² of gelatin, 0.003 g/m² of the following nucleating agent, and 0.02 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt,

Nucleating Agent

(5) a red-sensitive emulsion layer containing 0.23 g/m² in terms of silver of a red-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0.98 µm), 0.4 g/m² of gelatin, 0.04 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt, and 0.005 mg/m² of the same nucleating agent as used in layer (4),
(6) a color mixing preventing layer containing 0.61 g/m² of 2,5-di-t-pentadecylhydroquinone, 0.33 g/m² of the following polymer dispersant, and 0.3 g/m² of gelatin,

Polymer Dispersant

(molecular weight: 300,000)
(7) an interlayer containing 0.2 g/m² of gelatin,
(8) a color material layer containing 0.46 g/m² of the following magenta dye-releasing redox compound, 0.04 g/m² of the same Auxiliary Dispersant (A) as in layer (2), 0.07 g/m² of the same Auxiliary Dispersant (B) as in layer (2), and 0.7 g/m² of gelatin,

Magenta Dye-Releasing Redox Compound

(9) a green-sensitive emulsion layer containing 0.11 g/m² in terms of silver of a green-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0.65 µm), 0.2 g/m² of gelatin, 0.005 mg/m² of the same nucleating agent as in layer (4) and 0.02 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt,
(10) a green-sensitive emulsion layer containing 0.26 g/m² in terms of silver of a green-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0.98 µm), 0.6 g/m² of gelatin, 0.004 mg/m² of the same nucleating agent as in layer (4) and 0.04 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt,
(11) a color mixing preventing layer containing 0.91 g/m² of 2,5-di-t-pentadecylhydroquinone, 0.29 g/m² of the following polymer dispersant, and 0.4 g/m² of gelatin,

Polymer Dispersant

(molecular weight: 200,000)
(12) a layer the same as (7),
(13) a color material layer containing 0.53 g/m² of the following yellow dye-releasing redox compound, 0.16 g/m² of tricyclohexyl phosphate, 0.05 g/m² of the same Auxiliary Dispersant (A) as in layer (2), 0.03 g/m² of the same Auxiliary Dispersant (B) as in layer (2), and 0.5 g/m² of gelatin,

Yellow Dye-Releasing Redox Compound

(14) a blue-sensitive emulsion layer containing 0.15 g/m² in terms of silver of a blue-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0.65 µm), 0.2 g/m² of gelatin, 0.006 mg/m² of the same nucleating agent as in layer (4) and 0.01 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt,
(15) a blue-sensitive emulsion layer containing 0.23 g/m² in terms of silver of a blue-sensitive internal latent image type direct positive silver bromide emulsion (average grain size: 0.98 µm), 0.3 g/m² of gelatin, 0.005 mg/m² of the same nucleating agent as in layer (4) and 0.01 g/m² of 2-sulfo-5-n-pentadecylhydroquinone sodium salt,
(16) an ultraviolet absorbing layer containing 0.12 g/m² of the following Ultraviolet Absorbing Agents (A) and (B) respectively, and 0.5 g/m² of gelatin, and

Ultraviolet Absorbing Agent (A)

Ultraviolet Absorbing Agent (B)

(17) a protective layer containing 0.2 g/m² of a matting agent (polymethyl methacrylate (PMMA)), 0.11 g/m² of the following Hardening Agent (A), 0.03 g/m² of the following Hardening Agent (B), and 0.4 g/m² of gelatin.

Hardening Agent (A)

Hardening Agent (B)

A paper support having a thickness of 150 µm laminated with 20 µm-thick polyethylene was coated with the following layers to prepare an image-receiving element Sample No. 301.

Backing Layer Side:

(a) a light-shielding layer containing 2.8 g/m² of carbon black and 4.8 g/m² of gelatin,
(b) a white reflective layer containing 4.1 g/m² of titanium dioxide and 1.0 g/m² of gelatin,
(c) a protective layer containing 0.5 g/m² of gelatin,

Image-Receiving Layer Side:

(1) a neutralization layer containing 4.0 g/m² of an acrylic acid/butyl acrylate copolymer (molar ratio: 8/2, average molecular weight: 50,000), polyvinyl alcohol (polymerization degree: 500, saponification degree: 88%) and 0.04 g/m² of the following Hardening Agent (F),

Hardening Agent (F)

(2) a timing layer containing 3.5 g/m² of diacetyl cellulose (acetylation degree: 51.3%), 0.39 g/m² of styrene/maleic anhydride copolymer (molar ratio: 1/1, average molecular weight: 10,000), 0.07 g/m² of the following Compound (B), and 0.098 g/m² of CORONATE HL (manufactured by Nippon Polyurethane Co., Ltd.),

Compound (B)

(3) a timing layer containing 1.32 g/m² of a polymer latex obtained by emulsion polymerization of styrene/butyl acrylate/N-methylolacrylamide in a weight ratio of 49.7/42.3/8, 1.32 g/m² of a polymer latex obtained by emulsion polymerization of methyl methacrylate/acrylic acid/N-methylolacrylamide in a weight ratio of 93/3/4, 0.162 g/m² of the following Compound (C), and 0.0148 g/m² of the following Coating Aid (D),

Compound (C)

Coating Aid (D)

(4) a mordant layer containing 3.7 g/m² of the following Mordant (E), 0.21 g/m² of formaldehyde, 0.10 g/m² of the above Hardening Agent (F), 0.01 g/m² of the above Coating Aid (D), and 2.8 g/m² of gelatin, and

Mordant (E)

(5) a peeling-off layer containing 0.06 g/m² of an acrylic acid/butyl methacrylate copolymer (molar ratio: 85/15, average molecular weight: 100,000), and 0.003 g/m² of the following Compound (H).

Compound (H)

Further, an alkali treating composition was prepared. Each pod of aluminum foil laminated with vinyl chloride was filled with 1 g of the treating solution having the following composition under a nitrogen atmosphere.

Hydroxyethyl Cellulose	42 g
Zinc Nitrate·6H₂O	0.9 g
5-Methylbenzotriazole	5.4 g
Benzyl Alcohol	3.4 ml
Titanium Dioxide	1.2 g
Aluminum Nitrate·9H₂O	15 g
Potassium Sulfite	1.0 g
1-Phenyl-4-hydroxy-4-hydroxymethyl-3-pyrazolidone	13.0 g
Potassium Hydroxide	63 g
Water	854 ml

Then, after Photosensitive Element No. 301 was imagewise exposed, Photosensitive Element No. 301 was superposed on Image-Receiving Element No. 301 and the above-described treating solution was developed between both elements to a thickness of 60 µm.
Processing was carried out at 25°C, and the photosensitive element was peeled off from the image-receiving element 90 seconds after processing.
In the above photosensitive element, when the compounds according to the present invention were used in combination in the red-sensitive emulsion layer, green-sensitive emulsion layer and blue-sensitive emulsion layer, an image having high Dmax and low Dmin hence excellent in discrimination could be obtained similar to Example 1.
A color diffusion transfer photosensitive material and a color diffusion transfer film unit exhibiting short image-appearance time, high Dmax and low Dmin hence excellent in discrimination can be obtained according to the present invention.

Claims

A color diffusion transfer photographic material which comprises a support having provided thereon at least two internal latent image type direct positive photosensitive silver halide emulsion layers each containing a nucleating agent and being associated with a nondiffusible dye or a precursor thereof relating to silver development, or a dye image-forming compound the diffusibility of which changes relating to silver development, wherein said photographic material contains a compound represented by the following formula (I) and at least one oxidizing agent represented by the following formula (II), (III) or (IV):
wherein EAG represents an electron-accepting group; N and O represent a nitrogen atom and an oxygen atom respectively, and the N-O bond cleaves when EAG accepts an electron from a reducing agent; R¹ and R² each represents a substituent other than a hydrogen atom, when R¹ or R² is bonded to - (Time)_t-DIG, each represents a single bond or a divalent substitutent, R¹ and R² may be bonded to each other to form a ring, and R¹ and EAG, or R² and EAG may be bonded to each other to form a ring; Time represents a group which releases DIG through the reaction following after said cleavage between nitrogen and oxygen; DIG represents a moiety which becomes a development inhibitor as a result of being released; t represents 0 or 1; and a solid line represents a bond, and a broken line represents that at least one is bonded;
wherein R²¹, R²², ²³ and R²⁴ each represents a hydrogen atom, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkoxyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkylthio group having from 1 to 10 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted aryloxy group, a halogen atom, or a cyano group, R²¹ and R²², or R²³ and R²⁴ may be bonded to each other to form a ring;
wherein D¹ and D², which may be the same or different, each represents an atomic group necessary for forming a benzene ring or a naphthalene ring; G¹ and G², which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; A¹, A² and A³, which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; B¹, B² and B³, which may be the same or different, each represents a hydrogen atom or an arbitrary substituent which does not cause photographically maleficent influence; L¹ and L², which may be the same or different, each represents a linking group; m and n each represents 0 or 1; and M¹ and M², which may be the same or different, each represents a component having a function of releasing an azo compound from a compound represented by formula (III) as a result of development, or a hydrogen atom;
wherein EAG represents an electron-accepting group; N and O represent a nitrogen atom and an oxygen atom respectively, and the N-O bond cleaves when EAG accepts an electron from a reducing agent; and R⁴¹ and R⁴² each represents a substituent other than a hydrogen atom, R⁴¹ and R⁴², R⁴¹ and EAG, or R⁴² and EAG may be bonded to each other to form a ring; which is
a color diffusion transfer film unit comprising a photosensitive sheet (1) comprising a transparent support having provided thereon an image-receiving layer, a white reflective layer, a light-shielding layer, at least two photosensitive silver halide emulsion layers associated with said dye image-forming compound, and a compound represented by formula (I) and at least one oxidizing agent represented by formula (II), (III) or (IV), a transparent cover sheet (2) comprising a transparent support having provided thereon at least a neutralization layer and a neutralization timing layer, and a light-shielding alkali treating composition (3) which is arranged so as to develop between said photosensitive sheet (1) and said transparent cover sheet (2), or
a color diffusion transfer film unit comprising an image-receiving sheet (1) comprising a support having provided thereon at least a neutralization layer, a neutralization timing layer, an image-receiving layer and a peeling-off layer, a photosensitive sheet (2) comprising a light-shielding support having provided thereon at least two photosensitive silver halide emulsion layers associated with said dye image-forming compound, and a compound represented by formula (I) and at least one oxidizing agent represented by formula (II), (III) or (IV), and an alkali treating composition (3) which is arranged so as to develop between said image-receiving sheet (1) and said photosensitive sheet (2).
The color diffusion transfer photographic material as claimed in claim 1, wherein said compound represented by the formula (I) is a compound represented by the following formula (Ia):
wherein R³ represents an atomic group necessary for forming a 3-to 8-membered monocyclic or condensed heterocyclic ring by bonding to a nitrogen atom and an oxygen atom; and EAG, TIME, DIG and t have the same meaning as those in the formula (I).
The color diffusion transfer photographic material as claimed in claim 1, wherein EAG is represented by the following formula (A) or (B):

wherein Q¹ represents
V_n' represents an atomic group to form a 3- to 8-membered ring together with Q¹ and Q², n' represents an integer of from 3 to 8, here V₃ represents -Q³-, V₄ represents -Q³-Q⁴-, V₅ represents -Q³-Q⁴-Q⁵-, V₆ represents -Q³-Q⁴-Q⁵-Q⁶-, V₇ represents -Q³-Q⁴-Q⁵-Q⁶-Q⁷-, and V₈ represents -Q³-Q⁴-Q⁵-Q⁶-Q⁷-Q⁸- , Q², Q³, Q⁴, Q⁵, Q⁶, Q⁷ and Q⁸ each represents -C(Sub)₂-, -N (Sub) -, -O-, -S- or -SO₂-, and Sub represents a single bond (a κ bond), a hydrogen atom, or a substituent; and n" represents an integer of from 1 to 6, here U₁ represents -Y¹, U₂ represents -Y¹-Y², U₃ represents -Y¹-Y²-Y³, U₄ represents -Y¹-Y²-Y³-Y⁴, U₅ represents -Y¹-Y²-Y³-Y⁴-Y⁵, and U₆ represents -Y¹-Y²-Y³-Y⁴-Y⁵-Y⁶, Y¹, Y², Y³, Y⁴, Y⁵ and Y⁶ each represents -C(Sub')₃ or -N (Sub')₂, and Sub'represents a single bond (a σ bond, a κ bond) or a substituent.
The color diffusion transfer photographic material as claimed in claim 2, wherein said compound represented by the formula (Ia) is a compound represented by the following formula (Ib):
wherein EAG, Time, t and DIG have the same meaning as those in formula (Ia); X represents a divalent linking group; and R⁴ and R⁵ each represents a hydrogen atom or a substitutable group, and R⁴ and R⁵ may be bonded to each other to form a saturated or unsaturated carbocyclic ring or a heterocyclic ring.
The color diffusion transfer photographic material as claimed in claim 1, wherein D¹ and D², which may be the same or different, each represents an atomic group necessary to form a benzene ring or a naphthalene ring; at least one of G¹ and G² represents an electron-attractive atom or group having a Hammett's σ value of the same with or higher than that of a fluorine atom, and when either of G¹ or G² represents an electron-attractive atom or group, the other represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, a cyano group, a nitro group, -SO₂R³¹ (R³¹ represents an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, or a substituted aralkyl group), -NHCOR³¹ (R³¹ has the same meaning as above), -NHSO₂R³¹ (R³¹ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³, which may be the same or different, each represents a hydrogen atom, an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, or a substituted aralkyl group), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above) ; A¹, A² and A³, which may be the same or different, each represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, -NHCOR³¹ (R³¹ has the same meaning as above), -NHSO₂R³¹ (R³¹ has the same meaning as above) , -SO₂R³¹ (R³¹ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above); B¹, B² and B³, which may be the same or different, each represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group, an alkoxyl group, -SO₂R³¹ (R³¹ has the same meaning as above), -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above); L¹ and L² is represented by -[J¹-K¹-(J²-K²)_p-(J³-K³)_q-]_r-. J¹, J² and J³, which may be the same or different, each represents -CO-, -SO₂-, -CONH-, -SO₂NH-, -NHCO- or -NHSO₂-, K¹, K² and K³, which may be the same or different, each represents an alkylene group, an arylene group, or a substituted arylene group, and p, q and r each represents 0 or 1; and M¹, M², m and n have the same meaning as those in the formula (III).
The color diffusion transfer photographic material as claimed in claim 5, wherein D¹ represents an atomic group necessary to form a benzene ring or a naphthalene ring, D² represents an atomic group necessary to form a benzene ring; at least one of G¹ and G² represents a halogen atom, and when either one alone of G¹ or G² represents a halogen atom, the other represents a hydrogen atom, an alkyl group, or an alkoxyl group; A¹, A² and A³, which may be the same or different, each represents a hydrogen atom, a halogen atom, an alkyl group, a cyano group, -NHCOR³⁵ (R³⁵ represents an alkyl group or a phenyl group), -NHSO₂R³⁵ (R³⁵ has the same meaning as above), -SO₂N(R³²)(R³³) (R³² and R³³, which may be the same or different, each represents a hydrogen atom, an alkyl group, a substituted alkyl group, a phenyl group, a substituted phenyl group, an aralkyl group, or a substituted aralkyl group), or -CON (R³²)(R³³) (R³² and R³³ have the same meaning as above); B¹, B² and B³, which may be the same or different, each represents a hydrogen atom, a cyano group, a halogen atom, a nitro group, an alkyl group, -SO₂R³⁵ (R³⁵ has the same meaning as above) -CON(R³²)(R³³) (R³² and R³³ have the same meaning as above), or -SO₂N(R³²)(R³³) (R³² and R³³ have the same meaning as above), L¹ and L² is represented by -[J¹-K¹-(J²-K²)_p-(J³-K³)_q-]_r-, J¹ and J², which may be the same or different, each represents -CO-, -SO₂-, -CONH-, -SO₂NH-, -NHCO- or -NHSO₂-, K¹ and K², which may be the same or different, each represents a phenylene group, a substituted phenylene group, or an alkylene group, p and r each represents 0 or 1, and q represents 0; when M¹ and M² each represents a group other than a hydrogen atom, M¹ and M² each represents a group represented as (ballast)-(a redox-cleaving atomic group)-, (Ballast)- is a group for substantially immobilizing the compound represented by the formula (III) in a photographic layer, and -(A redox-cleaving atomic group)- has a property to be cut by oxidation or reduction by heat or under an alkaline condition, or a property of separating an azo compound moiety bonded thereto by cyclization; and m and n have the same meaning as those in the formula (III).
The color diffusion transfer photographic material as claimed in claim 1, wherein the compound represented by the formula (IV) is the compound represented by the following formula (IVa):
wherein EAG represents an electron-accepting group; N and O represent a nitrogen atom and an oxygen atom respectively, and the N-O bond cleaves when EAG accepts an electron from a reducing agent;R⁴³ represents an atomic group necessary to form a 3- to 8-membered monocyclic or condensed heterocyclic ring together with a nitrogen atom and an oxygen atom, and R⁴³ may be bonded to EAG to form a ring.
The color diffusion transfer photographic material as claimed in claim 7, wherein the compounds represented by the formula (IVa) is the compound represented by the following formula (IVb):
wherein EAG is the same meaning as that in the formula (IVa); X' represents a divalent linking group; and R⁴⁴ and R⁴⁵ each represents a hydrogen atom or a group substitutable with a hydrogen atom, and they may be bonded to each other to form a saturated or unsaturated carbocyclic ring or heterocyclic ring.
The color diffusion transfer photographic material as claimed in claim 1, wherein said compounds represented by the formulae (I), (II), (III) and (IV) are contained in a layer containing silver halide or an adjacent layer thereto.
The color diffusion transfer photographic material as claimed in claim 9, wherein said compounds represented by the formulae (I), (II), (III) and (IV) are contained in a silver halide emulsion layer.
The color diffusion transfer photographic material as claimed in claim 1, wherein the molar ratio of the compound represented by the formula (II), (III) or (IV) to the compound represented by the formula (I) is from 0.1 to 10.
The color diffusion transfer photographic material as claimed in claim 11, wherein the molar ratio of the compound represented by the formula (II), (III) or (IV) to the compound represented by the formula (I) is from 0.5 to 5.