A heat-developable light-sensitive material comprising a support having thereon at least one light-sensitive silver halide emulsion and an acid precursor having a structural moiety represented by the following formula (I) bonded to carbon atoms: ##STR1## The acid precursor is extremely stable at room temperature but when it is heated above a certain temperature, and the development proceeds to the desired appropriate condition, it releases an acid to neutralize a base, whereby the development is stopped. A heat-developable light-sensitive material containing the acid precursor provides color images having a high S/N ratio and a high image density.

FIELD OF THE INVENTION 
The present invention relates to a heat-developable light-sensitive 
material, particularly to a heat-developable light-sensitive material 
which has stable photographic properties after development processing. 
BACKGROUND OF THE INVENTION 
Photographic processes using silver halide have been widely used in the 
past due to their excellent photographic properties such as sensitivity or 
control of gradation, etc., as compared with other photographic processes, 
such as an electrophotographic process or a diazo photographic process. In 
recent years, with respect to image formation processes for 
light-sensitive materials using silver halide, many techniques capable of 
easily and quickly providing images have been developed by changing the 
conventional wet process using a developing solution into a dry 
development process such as a process using heat, etc. 
Heat-developable light-sensitive materials are thus well known in this 
field. Heat-developable light-sensitive materials and processes therefor 
have been described, for example, in Shashin Kogaku no Kiso (The 
Foundation of Photographic Technology), pages 553-555 (published by Corona 
Co., 1979), Eizo Joho (The Image Information), page 40 (April, 1978), 
Nebletts Handbook of Photography and Reprography, 7th Ed., pages 32-33 
(Van Nostrand Reinhold Company), U.S. Pat. Nos. 3,152,904, 3,301,678, 
3,392,020 and 3,457,075, British Pat. Nos. 1,131,108 and 1,167,777, and 
Research Disclosure, No. 17029, pages 9-15 (June, 1978). 
Many different processes for obtaining color image have been proposed. With 
respect to processes for forming color codes by the reaction of an 
oxidation product of a developing agent with a coupler, it has been 
proposed to use a p-phenylenediamine type reducing agent and a phenolic 
coupler or an active methylene coupler as described in U.S. Pat. No. 
3,531,286, a p-aminophenol type reducing agent as described in U.S. Pat. 
No. 3,761,270, a sulfonamidophenol type reducing agent as described in 
Belgian Pat. No. 802,519 and Research Disclosure, pages 31-32 (Sept., 
1975) and the combination of a sulfonamidophenol type reducing agent and a 
4-equivalent coupler as described in U.S. Pat. No. 4,021,240. 
Also, processes and materials for forming a positive color image by a 
light-sensitive silver dye bleach process are described, for example, in 
Research Disclosure, No. 14433, pages 30-32 (April, 1976), ibid., No. 
15227, pages 14-15 (December, 1976) and U.S. Pat. No. 4,235,957, etc. 
Further, processes for forming images upon heat-development utilizing 
compounds having a dye moiety which are capable of releasing a mobile dye 
in correspondence or counter-correspondence to the reduction reaction of 
silver halide to silver under temperature conditions have been described, 
for example, in European Patent Application (OPI) Nos. 76,492 and 79,056, 
Japanese Patent Application (OPI) Nos. 28928/83 and 26008/83, etc. (the 
term "OPI" as used herein refers to a "published unexamined patent 
application open to public inspection"). 
With these heat-develoapble light-sensitive materials development is 
conducted by heating. However, light-sensitive materials once heated at 
high temperature take a substantial time to decrease in temperature, 
resulting in overdevelopment or deterioration of image quality. Further, 
it is possible for development to occur beyond the desired level depending 
on subtle variations in conditions such as ambient temperature, 
temperature of heating, moisture content of the light-sensitive material, 
time of heating, etc., even when the same pattern of heating is employed. 
In order to eliminate such a phenomenon in the similar techniques, it has 
been proposed to use compounds which react with an alkali material to 
release a development stopping agent as described in U.S. Pat. No. 
4,009,029, or acid polymers for neutralization as described in Research 
Disclosure, Vol. 123, page 22, ibid., Vol. 180, page 18030 and British 
Pat. No. 2,082,787A. In heat-developable light-sensitive materials, 
however, the former do not effectively stop development and the latter 
cause a reduction in the density of the image obtained because the bases 
are rapidly neutralized. 
The most effective development stopping means conceivable is to perform 
development in the presence of a compound which releases an acid at an 
appropriate time of development to neutralize the base which promotes 
development, thus stopping development. Very few compounds are known, 
however, which release acids when heated. For example, in Japanese Patent 
Application (OPI) Nos. 58642/74 and 57452/75, there are disclosed acid 
components which at a temperature of at least 60.degree. C. are dissolved 
or release volatile acids. However, since the compounds disclosed in these 
patent applications neutralize the bases before development is started by 
heating, development is restrained and the density of the image obtained 
is reduced. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a novel 
heat-developable light-sensitive material which has the effect of stopping 
development when the development has sufficiently proceeded without 
reducing density of the resulting image. 
More specifically, one object of the present invention is to provide a 
heat-developable light-sensitive material containing a novel acid 
precursor which is extremely stable at room temperature but when it is 
heated above a certain temperature development proceeds till the 
appropriate condition whereupon it releases an acid to neutralize a base 
and stop development. 
Another object of the present invention is to provide a heat-developable 
light-sensitive material which provides an image having a high S/N ratio 
and high image density. 
Other objects of the present invention will become apparent from the 
following detailed description and examples. 
These objects of the present invention are achieved by a heat-developable 
light-sensitive material comprising a support having thereon at least 
light-sensitive silver halide emulsion and an acid precursor having a 
structural moiety represented by the following formula (I) bonded to 
carbon atoms. 
##STR2## 
DETAILED DESCRIPTION OF THE INVENTION 
Of the acid precursors according to the present invention, those preferred 
are represented by the following general formula (A): 
##STR3## 
wherein R.sup.1 represents a group selected from an alkyl group including 
a substituted alkyl group, a cycloalkyl group including a substituted 
cycloalkyl group, an aralkyl group including a substituted aralkyl group, 
an alkenyl group including a substituted alkenyl group, an aryl group 
including a substituted aryl group and a heterocyclic group including a 
substituted heterocyclic group; R.sup.2 represents a mono-, di- or 
trivalent residue selected from an alkyl group including a substituted 
alkyl group, a cycloalkyl group including a substituted cycloalkyl group, 
an aralkyl group including a substituted aralkyl group, an aryl group 
including a substituted aryl group, a heterocyclic group including a 
substituted heterocyclic group and a group formed by combining the 
foregoing groups; and n represents an integer of 1, 2 or 3. 
In R.sup.1 and R.sup.2, a preferred alkyl group is a straight chain or 
branched chain alkyl group having from 1 to 18 carbon atoms. Specific 
examples include an ethyl group, an n-propyl group, an n-butyl group, an 
n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-decyl group, 
an n-dodecyl group, etc. Substituents on the substituted alkyl group 
include, for example, a halogen atom, an alkoxy group, a cyano group, a 
substituted or unsubstituted carbamoyl group, a hydroxyl group, a carboxyl 
group, etc. 
In R.sup.1 and R.sup.2, a preferred cycloalkyl group is a 5-membered or 
6-membered unsubstituted or substituted cycloalkyl group having from 5 to 
10 carbon atoms. Specific examples include a cyclopentyl group, a 
cyclohexyl group, etc. 
Specific examples of the aralkyl groups include a benzyl group, a 
.beta.-phenethyl group, etc. 
Specific examples of the alkenyl groups include a vinyl group, an allyl 
group, a crotyl group, a substituted or unsubstituted styryl group, etc. 
In R.sup.1 and R.sup.2, a preferred aryl group is an aryl group having from 
6 to 18 carbon atoms. Specific examples include a phenyl group, a naphthyl 
group, an anthryl group, etc. Substituents on the substituted aryl group 
include, for example, a substituted or unsubstituted alkyl group, a 
substituted or unsubstituted alkoxy group, a substituted or unsubstituted 
aryl group, a halogen atom, a hydroxy group, a mercapto group, an amino 
group, a substituted amino group substituted with an alkyl group or an 
aryl group, an acylamino group, a sulfonylamino group, a cyano group, a 
nitro group, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, 
an oxycarbonyl group, a carbonyloxy group, a substituted or unsubstituted 
carbamoyl group, a substituted or unsubstituted sulfamoyl group, etc. 
In R.sup.1 and R.sup.2, specific examples of the heterocyclic group include 
a pyridyl group, a furyl group, a thienyl group, a pyrrole group, an 
indolyl group, etc. The heterocyclic group may be substituted with the 
substituents defined for the above-described substituted aryl group. 
Of the above-described groups for R.sup.1 and R.sup.2, an aryl group, a 
substituted aryl group and a heterocyclic group are preferred, and further 
a phenyl group, a substituted phenyl group, a naphthyl group and a 
substituted naphthyl group are particularly preferred. 
When heated at a temperature of higher than 60.degree. C., preferably 
higher than 100.degree. C., the acid precursor according to the present 
invention undergoes Lossen rearrangement to release a carboxylic acid in 
accordance with the following reaction scheme. 
##STR4## 
The reaction described above proceeds only by heating and is greatly 
accelerated in the presence of a base. The acids released form salts of 
carboxylic acids together with the bases, whereby a neutralization 
function is achieved as illustrated in the following scheme. 
EQU R.sup.2 (COOH).sub.n +nB:.fwdarw.nBH.sup..sym. +R.sup.2 
(COO.sup..crclbar.).sub.n 
wherein B: represents a base. 
It is known that potassium salts of the compounds represented by general 
formula (A) undergo Lossen rearrangement to provide salts of carboxylic 
acids. Investigations regarding the chemical kinetics of the reaction have 
been made in greater detail as described, for example, in Journal of 
American Chemical Society, Vol. 59, page 2308 (1937), ibid., Vol. 61, page 
618 (1939), etc. 
However, it has now been found for the first time that the compounds 
represented by general formula (A) function as effective acid precursors 
which are extremely stable at room temperature and, when heated in the 
presence of a base, efficiently release acids. These compounds are 
particularly effective as acid precursors employed in heat-developable 
light-sensitive materials the development of which is accelerated upon the 
release of bases from base precursors by heating, since they are stable at 
room temperature (due to the absence of a base) but when heated, they 
undergo a reaction to release acids which is accelerated by the base(s) 
released by the heating and form carboxylic acid salts of the bases, 
whereby the desired neutralization function is achieved.

Specific examples of the acid precursors according to the present invention 
are shown below. The present invention, however, is not to be construed as 
being limited to these specific examples. 
##STR5## 
Methods for syntheses of the acid precursors according to the present 
invention will be described below. 
The acid precursors according to the present invention can be synthesized 
by the condensation reaction of hydroxamic acid derivatives or salts 
thereof (C) with carboxylic acid halides as illustrated in the following 
reaction scheme. 
##STR6## 
wherein X represents a halogen atom; M.sup..sym. represents K.sup..sym., 
Na.sup..sym., etc., and R.sup.1 and R.sup.2 each has the same meaning as 
earlier defined. 
The reaction of hydroxamic acid derivatives or salts thereof with 
carboxylic acid halides can be carried out using various solvents. Of the 
solvents, acetonitrile, N,N-dimethylacetamide, N,N-dimethylformamide, 
etc., are particularly preferred because of the rapidity of reaction and 
the high yield. 
The hydroxamic acid derivatives or metal salts thereof used can be obtained 
by reaction of the corresponding carboxylic acid esters (D) with free 
hydroxylamine as described, for example, in Journal of American Chemical 
Society, Vol. 59, page 2308 (1937), and ibid., Vol. 61, page 618 (1939), 
etc., illustrated by the following reaction scheme. 
##STR7## 
wherein --R.sup.3 represents --CH.sub.3, --CH.sub.2 CH.sub.3, 
##STR8## 
etc.; and R.sup.1 has the same meaning as earlier defined. 
Specific synthesis examples of the acid precursors are set forth below. 
Unless otherwise indicated, all parts, percents, ratios and the like are 
by weight. 
SYNTHESIS EXAMPLE 1 
Synthesis of Acid Precursor (1) 
To 100 ml of an acetonitrile solution containing 25 g (0.182 mol) of 
benzohydroxamic acid was dropwise added 26 g (0.185 mol) of benzoyl 
chloride, and then the mixture was refluxed by heating for 2 hours. After 
the completion of the generation of hydrogen chloride gas, the reaction 
mixture was cooled with ice. The crystals thus precipitated were collected 
by filtration and washed with acetonitrile to obtain 38.7 g (0.16 mol) of 
Acid Precursor (1). 
SYNTHESIS EXAMPLE 2 
Synthesis of Acid Precursor (29) 
100 ml of an acetonitrile solution containing 20 g (0.091 mol) of potassium 
p-nitrobenzohydroxamate was cooled to 10.degree. C. and, while maintaining 
this temperature, 16 g (0.091 mol) of p-chlorobenzoyl chloride was 
dropwise added thereto. After the completion of the dropwise addition, the 
mixture was stirred at room temperature for 30 minutes and then refluxed 
by heating for 20 minutes. The reaction mixture was poured into water and 
the crystals thus precipitated were collected by filtration. These crude 
crystals were recrystallized from ethyl acetate to obtain 11.1 g (0.035 
mol) of Acid Precursor (29). 
SYNTHESIS EXAMPLE 3 
Synthesis of Acid Precursor (21) 
Synthesis of methyl p-methylsulfonylbenzoate: 
250 ml of a desiccated methanol solution containing 50 g (0.25 mol) of 
p-methylsulfonylbenzoic acid and 10 ml of concentrated sulfuric acid was 
refluxed by heating for 8 hours. The reaction mixture was then cooled with 
ice and the crystals thus precipitated were collected by filtration and 
washed with methanol to obtain 48.2 g (0.225 mol) of the above described 
compound. 
Synthesis of p-methylsulfonylbenzohydroxamic acid: 
To 140 ml of a methanol solution containing 27.4 g (0.4 mol) of 
hydroxylamine hydrochloride was dropwise added 77 g (0.4 mol) of a 28% 
methanol solution of sodium methylate with stirring. After the completion 
of the dropwise addition, the mixture was cooled with ice and the 
inorganic salt thus precipitated was removed by filtration to prepare a 
methanol solution of the free hydroxylamine. To this solution was added 
21.4 g (0.1 mol) of methyl p-methylsulfonylbenzoate and the mixture was 
stirred at 55.degree. to 60.degree. C. for 1 hour while bubbling nitrogen 
gas therethrough and then refluxed for 3 hours. Then, the reaction mixture 
was cooled with ice and the crystals thus precipitated were collected by 
filtration. These crude crystals were recrystallized from water to obtain 
5.3 g (0.0247 mol) of the above described compound. 
Synthesis of Acid Precursor (21): 
30 ml of an acetonitrile solution containing 5.3 g (0.0247 mol) of 
p-methylsulfonylbenzohydroxamic acid obtained as described above and 4.4 g 
(0.025 mol) of p-chlorobenzoyl chloride was refluxed by heating for 2 
hours. The reaction mixture was then cooled with ice and the crystals thus 
precipitated were collected by filtration and washed with acetonitrile to 
obtain 6.5 g (0.0184 mol) of Acid Precursor (21). 
In the following, the melting points of several examples of the acid 
precursors are given. 
______________________________________ 
Melting Point 
Acid Precursor (.degree.C.) 
______________________________________ 
(1) 155 to 156 
(2) 143 to 144.5 
(9) 133 to 133.5 
(15) 161 to 162 
(21) 174 to 176 
(29) 174.5 
(32) 134 to 135 
______________________________________ 
The acid precursors according to the present invention generate acid 
efficiently while they are present in a substantially dry film. 
Accordingly, the acid precursors according to the present invention are 
advantageously used for inducing a chemical change by the acids generated 
upon heating. 
The amount of the acid precursors used in the present invention varies 
depending upon the specific precursor used and the system in which it is 
used, but it is generally not more than about 50% by weight, preferably 
not more than about 30% by weight and less than about 0.01% by weight, 
based on the total weight of the coating layers on the support. The acid 
precursors according to the present invention can be used either singly or 
in combination with each other. 
The acid precursors according to the present invention can be incorporated 
into a binder by dissolving them in a water-soluble organic solvent (such 
as methanol, ethanol, acetone, dimethylformamide, etc.) or a mixture of 
the organic solvent(s) and water. 
The acid precursors according to the present invention can also be 
incorporated in the form of fine particles into a binder. 
The acid precursors are preferably added to an emulsion layer or an 
intermediate layer. 
Preferred acid precursors according to the present invention are those 
which decompose not more than 80%, preferably not more than 50%, and more 
preferably not more than 20%, based on the total amount thereof present 
until the appropriate time when development has sufficiently proceeded 
without reducing density of the resulting images (at the time just before 
fog abruptly increases). 
In the present invention, it is particularly preferred to use various bases 
or base precursors as dye releasing assistants. 
The bases or precursors thereof can be used in a light-sensitive material 
and/or a dye fixing material. In the case of incorporating them in a 
light-sensitive material, it is particularly advantageous to use base 
precursors, and to add them to the layer containing the acid precursors or 
a layer adjacent to the layer containing the acid precursors. The term 
"base precursor" used herein means a substance which releases a base 
component by heating to a temperature of development, where the base 
component released may be any inorganic base or organic base. 
As examples of preferred bases, there are, as inorganic bases, hydroxides, 
secondary or tertiary phosphates, borates, carbonates, quinolinates and 
metaborates of alkali metals or alkaline earth metals; ammonium hydroxide; 
quaternary alkylammonium hydroxide; and other metal hydroxides; etc., and, 
as organic bases, aliphatic amines, aromatic amines, heterocyclic amines, 
amidines, cyclic amidines, guanidines, cyclic guanidines, etc. In the 
present invention, compounds having a pKa value of 8 or more are 
particularly useful. 
As the base precursors, substances which undergo reaction by heating to 
release a base, such as salts of an organic acid which is decarboxylated 
by heating to undergo decomposition and yield a base, or compounds which 
are decomposed by Lossen rearrangement or Beckmann rearrangement to 
release an amine, are used. 
As preferred base precursors, there are precursors of the above described 
organic bases. For example, there are salts of thermally decomposable 
organic acids such as trichloroacetic acid, propiolic acid, cyanoacetic 
acid, sulfonylacetic acid, acetoacetic acid, etc., and salts of 
2-carboxycarboxamide as described in U.S. Pat. No. 4,088,496, etc. 
Specific examples of preferred bases are set forth below, but the present 
invention should not be construed as being limited to these compounds. 
Lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, 
sodium carbonate, potassium carbonate, sodium quinolinate, potassium 
quinolinate, sodium secondary phosphate, potassium secondary phosphate, 
sodium tertiary phosphate, potassium tertiary phosphate, sodium 
pyrophosphate, potassium pyrophosphate, sodium metaborate, potassium 
metaborate, borax, ammonium hydroxide, tetramethyl ammonium, tetrabutyl 
ammonium, ammonia, MeNH.sub.2 (Me represents CH.sub.3 hereinafter), 
Me.sub.2 NH, EtNH.sub.2 (Et represents C.sub.2 H.sub.5 hereinafter), 
Et.sub.2 NH, C.sub.4 H.sub.9 NH.sub.2, (C.sub.4 H.sub.9).sub.2 NH, 
HOC.sub.2 H.sub.4 NH.sub.2, (HOC.sub.2 H.sub.4).sub.2 NH, Et.sub.2 
NCH.sub.2 CH.sub.2 OH, H.sub.2 NC.sub.2 H.sub.4 NH.sub.2, MeNHC.sub.2 
H.sub.4 NHMe, Me.sub.2 NCH.sub.4 NH.sub.2, H.sub.2 NC.sub.3 H.sub.6 
NH.sub.2, H.sub.2 NC.sub.4 H.sub.8 NH.sub.2, H.sub.2 NC.sub.5 H.sub.10 
NH.sub.2, Me.sub.2 NC.sub.2 H.sub.4 NMe.sub.2, Me.sub.2 NC.sub.3 H.sub.6 
NMe.sub.2, 
##STR9## 
Specific examples of preferred base precursors are set forth below, but the 
present invention should not be construed as being limited thereto. 
As trichloroacetic acid derivatives, there are guanidine trichloroacetic 
acid, piperidine trichloroacetic acid, morpholine trichloroacetic acid, 
p-toluidine trichloroacetic acid, 2-picoline trichloroacetic acid, etc. 
These compounds are believed to release a base by decarboxylation of the 
acid moiety. 
In addition, base precursors as described in British Pat. No. 998,945, U.S. 
Pat. No. 3,220,846, Japanese Patent Application (OPI) No. 22625/75, etc., 
can be used. 
As substances besides trichloroacetic acids, there are 2-carboxycarboxamide 
derivatives as described in U.S. Pat. No. 4,088,496, 
.alpha.-sulfonylacetate derivatives as described in U.S. Pat. No. 
4,060,420, salts of propiolic acid derivatives and bases as described in 
Japanese Patent Application No. 55700/83, etc. Salts using alkali metal or 
an alkaline earth metal as a base component other than organic bases are 
also effective. 
As other precursors, hydroxamic carbamates as described in Japanese Patent 
Application No. 43860/83 utilizing Lossen rearrangement and aldoxime 
carbamates as described in Japanese Patent Application No. 31614/83 which 
form a nitrile, etc., are effective. 
Further, amineimides as described in Research Disclosure, No. 15776 (May, 
1977) and aldonic amides as described in Japanese Patent Application (OPI) 
No. 22625/75 are suitably used, because they form a base by decomposition 
at a high temperature. 
These bases and base precursors can be used over a wide range. An effective 
range is not more than 50% by weight based on the total weight of the 
dried coating layers on the support in the light-sensitive material, and, 
preferably, a range of from 0.01% by weight to 40% by weight. 
According to the present invention, silver can be utilized as an image 
forming substance. Further, various other image forming substances can be 
employed in various image forming processes. 
For instance, couplers capable of forming color images upon reaction with 
an oxidation product of a developing agent which are used in liquid 
development processing widely known hitherto can be employed. For example, 
as magenta couplers, there are 5-pyrazolone couplers, 
pyrazolobenzimidazole couplers, cyanoacetylcoumarone couplers and open 
chain acylacetonitrile couplers, etc. As yellow couplers, there are 
acylacetamide couplers (for example, benzoylacetanilides and 
pivaloylacetanilides), etc. As cyan couplers, there are naphthol couplers 
and phenol couplers, etc. It is preferred that these couplers be 
nondiffusible substances which have a hydrophobic group called a ballast 
group in the molecule thereof or be polymerized substances. The couplers 
may be any of the 4-equivalent type and 2-equivalent type to silver ions. 
Further, they may be colored couplers having a color correction effect or 
couplers which release a development inhibitor at development processing 
(so-called DIR couplers). 
Further, dyes for forming positive color images by a light-sensitive silver 
dye bleach processes, for example, those as described in Research 
Disclosure, No. 14433, pages 30-32 (April, 1976), ibid., No. 15227, pages 
14-15 (December, 1976) and U.S. Pat. No. 4,235,957, etc., can be employed. 
Moreover, leuco dyes as described, for example, in U.S. Pat. Nos. 3,985,565 
and 4,022,617, etc., can be used. 
Further, dyes to which a nitrogen-containing heterocyclic group have been 
introduced as described in Research Disclosure, No. 16966, pages 54-58 
(May, 1978), may be employed. 
In addition, dye providing substances which release a mobile dye by 
utilizing a coupling reaction of a reducing agent oxidized by an oxidation 
reduction reaction with a silver halide or an organic silver salt at high 
temperature as described in European Pat. No. 79,056, West German Pat. No. 
3,217,853, European Pat. No. 67,455, etc., and dye providing substances 
which release a mobile dye as a result of an oxidation reduction reaction 
with a silver halide or an organic silver salt at high temperature as 
described in European Pat. No. 76,492, West German Pat. No. 3,215,485, 
European Pat. No. 66,282, Japanese Patent Application Nos. 28928/83 and 
26008/83, etc., can be employed. 
Thus, the term "reducing substance" as used herein includes dye providing 
substances and reducing agents, the latter being described herein below. 
Preferred dye providing substances which can be employed in these processes 
can be represented by the following general formula (CI): 
EQU (Dye--X).sub.q y (C I) 
wherein Dye represents a dye which becomes mobile when it is released from 
the molecule of the compound represented by the general formula (C I); X 
represents a simple bond or a connecting group; Y represents a group which 
releases Dye in correspondence or countercorrespondence to light-sensitive 
silver salts having a latent image distributed imagewise, the 
diffusibility of Dye released being different from that of the compound 
represented by formula (C I) and q represents an integer of 1 or 2. 
The dye represented by Dye is preferably a dye having a hydrophilic group. 
Examples of the dye which can be used include azo dyes, azomethine dyes, 
anthraquinone dyes, naphthoquinone dyes, styryl dyes, nitro dyes, 
quinoline dyes, carbonyl dyes and phthalocyanine dyes, etc. These dyes can 
also be used in the form of having temporarily shorter wavelengths, the 
color of which is recoverable in the development processing. 
More specifically, the dyes as described in European Patent Application No. 
76,492 can be utilized. 
Examples of the connecting group represented by X include --NR-- (wherein R 
represents a hydrogen atom, an alkyl group, or a substituted alkyl group), 
--SO.sub.2 --, --CO--, an alkylene group, a substituted alkylene group, a 
phenylene group, a substituted phenylene group, a naphthylene group, a 
substituted naphthylene group, --O--, --SO--, or a group derived by 
combining together two or more of the foregoing groups. 
In the following, preferred embodiments of Y in formula (C I) are described 
in greater detail. 
In one embodiment, Y is selected so that the compound represented by the 
general formula (C I) is a nondiffusible image forming compound which is 
oxidized as a result of development, thereby undergoing self-cleavage and 
releasing a diffusible dye. 
An example of Y which is effective for compounds of this type is an 
N-substituted sulfamoyl group. For example, a group represented by formula 
(C II) is illustrated for Y. 
##STR10## 
wherein 
.beta. represents non-metallic atoms necessary for forming a benzene ring, 
which may optionally be fused with a carbon ring or a hetero ring to form, 
for example, a naphthalene ring, a quinoline ring, a 
5,6,7,8-tetrahydronaphthalene ring, a chroman ring or the like. 
.alpha. represents a group of --OG.sup.11 or --NHG.sup.12 (wherein G.sup.11 
represents hydrogen or a group which forms a hydroxy group upon being 
hydrolyzed, and G.sup.12 represents hydrogen, an alkyl group containing 1 
to 22 carbon atoms or a hydrolyzable group), 
Ball represents a ballast group, and 
b represents an integer of 0, 1 or 2. 
Specific examples of this type of Y are described in Japanese Patent 
Application (OPI) Nos. 33826/73 and 50736/78. 
Other examples of Y suited for this type of compound are those represented 
by the following general formula (CIII): 
##STR11## 
wherein Ball, .alpha., and b are the same as defined with (CII), .beta.' 
represents atoms necessary for forming a carbon ring (e.g., a benzene ring 
which may be fused with another carbon ring or a hetero ring to form a 
naphthalene ring, quinoline ring, 5,6,7,8-tetrahydronaphthalene ring, 
chroman ring or the like. Specific examples of this type of Y are 
described in Japanese Patent Application (OPI) Nos. 113624/76, 12642/81, 
16130/81, 4043/82 and 650/82, and U.S. Pat. No. 4,053,312. 
Further examples of Y suited for this type of compound are those 
represented by the following formula (CIV): 
##STR12## 
wherein Ball, .alpha., and b are the same as defined with the formula 
(CII), and .beta." represents atoms necessary for forming a hetero ring 
such as a pyrazole ring, a pyridine ring or the like, said hetero ring 
being optionally bound to a carbon ring or a hetero ring. Specific 
examples of this type of Y are described in Japanese Patent Application 
(OPI) No. 104343/76. 
Still further examples of Y suited for this type of compound are those 
represented by the following formula (CV): 
##STR13## 
wherein .gamma. preferably represent hydrogen, a substituted or 
unsubstituted alkyl, aryl or heterocyclic group, or --CO--G.sup.21 ; 
G.sup.21 represents --OG.sup.22, --SG.sup.22 or 
##STR14## 
(wherein G.sup.22 represents hydrogen, an alkyl group, a cycloalkyl group 
or an aryl group, G.sup.23 is the same as defined for said G.sup.22, or 
G.sup.23 represents an acyl group derived from an aliphatic or aromatic 
carboxylic or sulfonic acid, and G.sup.24 represents hydrogen or an 
unsubstituted or substituted alkyl group); and .delta. represents a 
residue necessary for completing a fused benzene ring. 
Specific examples of this type of Y are described in Japanese Patent 
Application (OPI) Nos. 104343/76, 46730/78, 130122/79 and 85055/82. 
Still further examples of Y suited for this type of compound are those 
represented by the formula (CVI): 
##STR15## 
wherein Ball is the same as defined with the formula (CII); .epsilon. 
represents an oxygen atom or .dbd.NG.sup.32 (wherein G.sup.32 represents 
hydroxy or an optionally substituted amino group) (examples of H.sub.2 
N--G.sup.32 to be used for forming the group of .dbd.NG.sup.32 including 
hydroxylamine, hydrazines, semicarbazides, thiosemicarbazides, etc.); 
.beta."' represents a saturated or unsaturated nonaromatic 5-, 6- or 
7-membered hydrocarbon ring; and G.sup.31 represents hydrogen or a halogen 
atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, etc.). 
Specific examples of this type of Y are described in Japanese Patent 
Application (OPI) Nos. 3819/78 and 48534/79. 
Other examples of Y of this type of compound are described in Japanese 
Patent Publication Nos. 32129/73, 39165/73, Japanese Patent Application 
(OPI) No. 64436/74, U.S. Pat. No. 3,443,934, etc. 
Still further examples of Y are those represented by the following formula 
(CVII): 
##STR16## 
wherein .alpha. represents OR.sup.41 or NHR.sup.42 ; R.sup.41 represents 
hydrogen or a hydrolyzable component; R.sup.42 represents hydrogen or an 
alkyl group containing 1 to 50 carbon atoms; A.sup.41 represents atoms 
necessary for forming an aromatic ring; Ball represents an organic 
immobile group existing on the aromatic ring, with Ball's being the same 
or different from each other; m represents an integer of 1 or 2; X 
represents a divalent organic group having 1 to 8 atoms, with the 
nucleophilic group (Nu) and an electrophilic center (asterisked carbon 
atom) formed by oxidation forming a 5- to 12-membered ring; Nu represents 
a nucleophilic group; n represents an integer of 1 or 2; and .alpha. may 
be the same as defined with the above-described formula (CII). Specific 
examples of this type of Y are described in Japanese Patent Application 
(OPI) No. 20735/82. 
As still further type of examples represented by the formula of (CI), there 
are dye providing non-diffusible substances which release a diffusible dye 
in the presence of a base as a result of self cyliczation or the like but 
which, when reacted with an oxidation product of a developing agent, 
substantially never release the dye. 
Examples of Y effective for this type of compound are those which are 
represented by the formula (CVIII): 
##STR17## 
wherein 
.alpha.' represents an oxidizable nucleophilic group (e.g., a hydroxy 
group, a primary or secondary amino group, a hydroxyamino group, a 
sulfonamido group or the like) or a precursor thereof; 
.alpha." represents a dialkylamino group or an optional group defined for 
.alpha.'; 
G.sup.51 represents an alkylene group having 1 to 3 carbon atoms; 
a represents 0 or 1; 
G.sup.52 represents a substituted or unsubstituted alkyl group having 1 to 
40 carbon atoms or a substituted or unsubstituted aryl group having 6 to 
40 carbon atoms; 
G.sup.53 represents an electrophilic group such as --CO--or --CS--; 
G.sup.54 represents an oxygen atom, a sulfur atom, a selenium atom, a 
nitrogen atom or the like and, when G.sup.54 represents a nitrogen atom, 
it has hydrogen or may be substituted by an alkyl or substituted alkyl 
group having 1 to 10 carbon atoms or an aromatic residue having 6 to 20 
carbon atoms; and 
G.sup.55, G.sup.56 and G.sup.57 each represents hydrogen, a halogen atom, a 
carbonyl group, a sulfamyl group, a sulfonamido group, an alkyloxy group 
having 1 to 40 carbon atoms or an optional group defined for G.sup.52, 
G.sup.55 and G.sup.56 may form a 5- to 7-membered ring, and G.sup.56 may 
represent 
##STR18## 
with the proviso that at least one of G.sup.52, G.sup.55, G.sup.56 and 
G.sup.57 represents a ballast group. Specific examples of this type of Y 
are described in Japanese Patent Application (OPI) No. 63618/76. 
Further examples of Y suited for this type of compound are those which are 
represented by the following general formulae (CIX) and (CX): 
##STR19## 
wherein Nu.sup.61 and Nu.sup.62, which may be the same or different, each 
represents a nucleophilic group or a precursor thereof; Z.sup.61 
represents a divalent atom group which is electrically negative with 
respect to the carbon atom substituted by R.sup.64 and R.sup.65 ; 
R.sup.61, R.sup.62 and R.sup.63 each represents hydrogen, a halogen atom, 
an alkyl group, an alkoxy group or an acylamino group or, when located at 
adjacent positions on the ring, R.sup.61 and R.sup.62 may form a fused 
ring together with the rest of the molecule, or R.sup.62 and R.sup.63 may 
form a fused ring together with the rest of the molecule; R.sup.64 and 
R.sup.65, which may be the same or different, each represents hydrogen, a 
hydrocarbon group or a substituted hydrocarbon group; with at least one of 
the substituents, R.sup.61, R.sup.62, R.sup.63, R.sup.64 and R.sup.65 
having a ballast group, Ball, of an enough size so as to render the 
above-described compounds immobile. Specific examples of this type of Y 
are described in Japanese Patent Application (OPI) Nos. 69033/78 and 
130927/79. 
Further examples of Y suited for this type of compound are those which are 
represented by the formula of (CXI): 
##STR20## 
wherein 
Ball and .beta.' are the same as defined for those in formula (CIII), and 
G.sup.71 represents an alkyl group (including a substituted alkyl group). 
Specific examples of this type of Y are described in Japanese Patent 
Application (OPI) Nos. 111628/74 and 4819/77. 
As different type of compound represented by the general formula (CI), 
there are illustrated dye providing nondiffusible substances which 
themselves do not release any dye but, upon reaction with a reducing 
agent, release a dye. With these compounds, compounds which mediate the 
redox reaction (called electron donors) are preferably used in 
combination. 
Examples of Y effective for this type of compound are those represented by 
the formula (CXII): 
##STR21## 
wherein Ball and .beta.' are the same as defined for those in the general 
formula (CIII), and G.sup.71 represents an alkyl group (including a 
substituted alkyl group). Specific examples of this type of Y are 
described in Japanese Patent Application (OPI) Nos. 35533/78 and 
110827/78. 
Further examples of Y suited for this type of compound are those which are 
represented by (CXIII): 
##STR22## 
wherein .alpha.'.sub.ox and .alpha.".sub.ox represent groups capable of 
giving .alpha.' and .alpha.", respectively, upon reduction, and .alpha.', 
.alpha.", G.sup.51, G.sup.52, G.sup.53, G.sup.54, G.sup.55, G.sup.56, 
G.sup.57 and a are the same as defined with respect to formula (CVIII). 
Specific examples of Y described above are described in Japanese Patent 
Application (OPI) No. 110827/78, U.S. Pat. Nos. 4,356,249 and 4,358,525. 
Further examples of Y suited for this type of compound are those which are 
represented by the formulae (CXIVA) and (CXIVB): 
##STR23## 
wherein (Nuox).sup.1 and (Nuox).sup.2, which may be the same or different, 
each represents an oxidized nucleophilic group, and other notations are 
the same as defined with respect to the formulae (CIX) and (CX). Specific 
examples of this type of Y are described in Japanese Patent Application 
(OPI) Nos. 130927/79 and 164342/81. 
The publicly known documents having been referred to with respect to 
(CXII), (CXIII), (CXIVA) and (CXIVB) describe electron donors to be used 
in combination. 
As still further different type of compound represented by the general 
formula (CI), there are illustrated LDA compounds (Linked Donor Acceptor 
Compounds). These compounds are dye providing non-diffusible substances 
which cause donor-acceptor reaction in the presence of a base to release a 
diffusible dye but, upon reaction with an oxidation product of a 
developing agent, they substantially do not release the dye any more. 
Examples of Y effective for this type of compound are those represented by 
the formula of (CXV) (specific examples thereof being described in 
Japanese Patent Application (OPI) No. 60289/83): 
##STR24## 
wherein n, x, y and z each represents 1 or 2, m represents an integer of 1 
or more; Don represents a group containing an electron donor or its 
precursor moiety; L.sup.1 represents an organic group linking Nup to 
--El--Q or Don; Nup represents a precursor of a nucleophilic group; El 
represents an electrophilic center; Q represents a divalent group; Ball 
represents a ballast group; L.sup.2 represents a linking group; and 
M.sup.1 represents an optional substituent. 
The ballast group is an organic ballast group which can render the dye 
providing substance nondiffusible, and is preferably a group containing a 
C.sub.8-32 hydrophobic group. Such organic ballast group is bound to the 
dye providing substance directly or through a linking group (e.g., an 
imino bond, an ether bond a thioether bond, a carbonamido bond, a 
sulfonamido bond, a ureido bond, an ester bond, an imido bond, a carbamoyl 
bond, a sulfamoyl bond, etc., and combination thereof). 
Two or more kinds of the dye providing substances can be employed together. 
In such a case two or more kinds of the dye providing substances may be 
used together in order to provide the same hue or in order to reproduce 
black color. 
Specific examples of dye image forming substrates which can be used in the 
present invention are described in the patents cited hereinbefore. Since 
length prevents illustrating all preferred examples thereof, only a 
portion thereof is described hereinafter. Specific examples of the dye 
providing substances represented by general formula (CI) are set forth 
below. 
##STR25## 
The above described compounds are only given as examples and the present 
invention should not be construed as being limited thereto. 
Most of the dye image forming substance described above form an imagewise 
distributions of a mobile dye corresponding to exposure in light-sensitive 
materials by heat development. Methods for transfer of such image forming 
dyes to dye fixing material (so-called diffusion transfer) to visualize 
the same are described in the patents cited above. 
The dye releasing redox compound used in the present invention can be 
introduced into a layer of the light-sensitive material by known methods 
such as a method as described in U.S. Pat. No. 2,322,027. In this case, an 
organic solvent having a high boiling point or an organic solvent having a 
low boiling point as described below can be used. For example, the dye 
releasing redox compound is dispersed in a hydrophilic colloid after 
dissolved in an organic solvent having a high boiling point, for example, 
a phthalic acid alkyl ester (for example, dibutyl phthalate, dioctyl 
phthalate, etc.), a phosphoric acid ester (for example, diphenyl 
phosphate, triphenyl phosphate, tricresyl phosphate, dioctylbutyl 
phosphate, etc.), a citric acid ester (for example, tributyl 
acetylcitrate, etc.), a benzoic acid ester (for example, octyl benzoate, 
etc.), an alkylamide (for example, diethyl laurylamide, etc.), an 
aliphatic acid ester (for example, dibutoxyethyl succinate, dioctyl 
azelate, etc.), a trimesic acid ester (for example, tirubtyl trimesate, 
etc.), etc., or an organic solvent having a boiling point of about 
30.degree. C. to 160.degree. C., for example, a lower alkyl acetate such 
as ethyl acetate, butyl acetate, etc., ethyl propionate, secondary butyl 
alcohol, methyl isobutyl ketone, .beta.-ethoxyethyl acetate, methyl 
cellosolve acetate, cyclohexanone, etc. The above described organic 
solvents having a high boiling point and organic solvents having a low 
boiling point may be used as a mixture thereof. 
Further, it is possible to use a dispersion method using a polymer as 
described in Japanese Patent Publication No. 39853/76 and Japanese Patent 
Application (OPI) No. 59943/76. Moreover, various surface active agents 
can be used when the dye releasing redox compound is dispersed in a 
hydrophilic colloid. For this purpose, the surface active agents 
illustrated in other part of the specification can be used. 
The reducing agents used in the present invention include the following 
compounds. 
Hydroquinone compounds (for example, hydroquinone, 
2,5-dichlorohydroquinone, 2-chlorohydroquinone, etc.), aminophenol 
compounds (for example, 4-aminophenol, N-methylaminophenol, 
3-methyl-4-aminophenol, 3,5-dibromoaminophenol, etc.), catechol compounds 
(for example, catechol, 4-cyclohexylcatechol, 3-methoxycatechol, 
4-(N-octadecylamino)catechol, etc.), phenylenediamine compounds (for 
example, N,N-diethyl-p-phenylenediamine, 
3-methyl-N,N-diethyl-p-phenylenediamine, 
3-methoxy-N-ethyl-N-ethoxy-p-phenylenediamine, 
N,N,N',N'-tetramethyl-p-phenylenediamine, etc.). 
Various combinations of developing agents as described in U.S. Pat. No. 
3,039,869 can also be used. 
In the present invention, an amount of the reducing agent added is from 
0.01 mol to 20 mols per mol of silver and more preferably from 0.1 mol to 
10 mols per mol of silver. 
In the present invention, if necessary, the so-called auxiliary developing 
agent can be used even when the dye releasing redox compound is used. The 
auxiliary developing agent in this case is a compound which is oxidized 
upon the silver halide to form its oxidized product having an ability to 
oxidize the reducing group Ra in the dye releasing redox compound. 
Examples of useful auxiliary developing agents include the compounds 
specifically described in European Patent Application (OPI) No. 76,492. 
They can be used in an amount of 0.0005 time by mol to 20 times by mol 
based on silver. 
The silver halide used in the present invention includes silver chloride, 
silver chlorobromide, silver chloroiodide, silver bromide, silver 
iodobromide, silver chloroiodobromide and silver iodide, etc. 
The process for preparing those silver halides is explained taking the case 
of silver iodobromide. That is, the silver iodobromide is prepared by 
first adding silver nitrate solution to potassium bromide solution to form 
silver bromide particles and then adding potassium iodide to the mixture. 
Two or more kinds of silver halides in which a particle size and/or a 
halogen composition are different from each other may be used in mixture. 
An average particle size of the silver halide used in the present invention 
is preferably from 0.001 .mu.m to 10 .mu.m and more preferably from 0.001 
.mu.m to 5 .mu.m. 
The silver halide used in the present invention may be used as is. However, 
it may be chemically sensitized with a chemical sensitizing agent such as 
compounds of sulfur, selenium or tellurium, etc., or compounds of gold, 
platinum, palladium, rhodium or iridium, etc., a reducing agent such as 
tin halide, etc., or a combination thereof. The details thereof are 
described in T.H. James, The Theory of the Photographic Process, The 
Fourth Edition, Chapter 5, pages 149-169. 
In the particularly preferred embodiment of the present invention, an 
organic silver salt oxidizing agent is used together. The organic silver 
salt oxidizing agent is a silver salt which forms a silver image by 
reacting with the above described image forming substance or a reducing 
agent coexisting, if necessary, with the image forming substance, when it 
is heated to a temperature of above 80.degree. C. and, preferably, above 
100.degree. C. in the presence of exposed silver halide. By coexisting the 
organic silver salt oxidizing agent, the light-sensitive material which 
provides higher color density can be obtained. 
Examples of such organic silver salt oxidizing agents include those 
described in European Patent Application (OPI) No. 76,492. 
A silver salt of an organic compound having a carboxyl group can be used. 
Typical examples thereof include a silver salt of an aliphatic carboxylic 
acid and a silver salt of an aromatic carboxylic acid. 
In addition, a silver salt of a compound containing a mercapto group or a 
thione group and a derivative thereof can be used. 
Further, a silver salt of a compound containing an imino group can be used. 
Examples of these compounds include a silver salt of benzotriazole and a 
derivative thereof as described in Japanese Patent Publication Nos. 
30270/69 and 18416/70, for example, a silver salt of benzotriazole, a 
silver salt of alkyl substituted benzotriazole such as a silver salt of 
methylbenzotriazole, etc., a silver salt of a halogen substituted 
benzotriazole such as a silver salt of 5-chlorobenzotriazole, etc., a 
silver salt of carboimidobenzotriazole such as a silver salt of 
butylcarboimidobenzotriazole, etc., a silver salt of 1,2,4-triazole or 
1-H-tetrazole as described in U.S. Pat. No. 4,220,709, a silver salt of 
carbazole, a silver salt of saccharin, a silver salt of imidazole and an 
imidazole derivative, and the like. 
Moreover, a silver salt as described in Research Disclosure, Vol. 170, No. 
17029 (June, 1978) and an organic metal salt such as copper stearate, 
etc., are the organic metal salt oxidizing agent capable of being used in 
the present invention. 
Methods of preparing these silver halide and organic silver salt oxidizing 
agents and manners of blending them are described in Research Disclosure, 
No. 17029, Japanese Patent Application (OPI) Nos. 32928/75 and 42529/76, 
U.S. Pat. No. 3,700,458, and Japanese Patent Application (OPI) Nos. 
13224/74 and 17216/75. 
A suitable coating amount of the light-sensitive silver halide and the 
organic silver salt oxidizing agent employed in the present invention is 
in a total of from 50 mg/m.sup.2 to 10 g/m.sup.2 calculated as an amount 
of silver. 
The binder which can be used in the present invention can be employed 
individually or in a combination thereof. A hydrophilic binder can be used 
as the binder according to the present invention. The typical hydrophilic 
binder is a transparent or translucent hydrophilic colloid, examples of 
which include a natural substance, for example, protein such as gelatin, a 
gelatin derivative, a cellulose derivative, etc., a polysaccharide such as 
starch, gum arabic, etc., and a synthetic polymer, for example, a 
water-soluble polyvinyl compound such as polyvinyl alcohol, polyvinyl 
pyrrolidone, acrylamide polymer, etc. Another example of the synthetic 
polymer compound is a dispersed vinyl compound in a latex form which is 
used for the purpose of increasing dimensional stability of a photographic 
material. 
Further, in the present invention, it is possible to use a compound which 
activates development simultaneously while stabilizing the image. 
Particularly, it is preferred to use isothiuroniums including 
2-hydroxyethylisothiuronium trichloroacetate as described in U.S. Pat. 
3,301,678, bisisothiuroniums including 
1,8-(3,6-dioxaoctane)-bis(isothiuronium trifluoroacetate), etc., as 
described in U.S. Pat. No. 3,669,670, thiol compounds as described in 
German Patent Application (OLS) No. 2,162,714, thiazolium compounds such 
as 2-amino-2-thiazolium trichloroacetate, 
2-amino-5-bromo-ethyl-2-thiazolium trichloroacetate, etc., as described in 
U.S. Pat. No. 4,012,260, compounds having .alpha.-sulfonylacetate as an 
acid part such as bis(2-amino-2-thiazolium)methylenebis(sulfonylacetate), 
2-amino-2-thiazolium phenylsulfonylacetate, etc., as described in U.S. 
Pat. No. 4,060,420, and compounds having 2-carboxycarboxamide as an acid 
part as described in U.S. Pat. No. 4,088,496. 
Various means of exposure can be used in the present invention. Latent 
images are obtained by image-wise exposure by radiant rays including 
visible rays. Generally, light sources used for conventional color prints 
can be used, examples of which include tungsten lamps, mercury lamps, 
halogen lamps such as iodine lamps, xenon lamps, laser light sources, CRT 
light sources, fluorescent tubes and light-emitting diodes, etc. 
In the present invention, after the heat-developable color photographic 
material is exposed to light, the resulting latent image can be developed 
by heating the whole material to a suitably elevated temperature, for 
example, about 80.degree. C. to about 250.degree. C. for about 0.5 second 
to about 300 seconds. A higher temperature or lower temperature can be 
utilized to prolong or shorten the heating time, if it is within the above 
described temperature range. 
As the heating means, a simple heat plate, iron, heat roller, heat 
generator utilizing carbon or titanium white, etc., or analogues thereof 
may be used. 
The silver halide used in the present invention can be spectrally 
sensitized with methine dyes or other dyes. Suitable dyes which can be 
employed include cyanine dyes, merocyanine dyes, complex cyanine dyes, 
complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl 
dyes, and hemioxonol dyes. Of these dyes, cyanine dyes, merocyanine dyes 
and complex merocyanine dyes are particularly useful. Any conventionally 
utilized nucleus for cyanine dyes, such as basic heterocyclic nuclei, is 
applicable to these dyes. That is, a pyrroline nucleus, an oxazoline 
nucleus, a thiazoline nucleus, a pyrrole nucleus, an oxazole nucleus, a 
thiazole nucleus, a selenazole nucleus, an imidazole nucleus, a tetrazole 
nucleus, a pyridine nucleus, etc., and further, nuclei formed by 
condensing alicyclic hydrocarbon rings with these nuclei and nuclei formed 
by condensing aromatic hydrocarbon rings with these nuclei, that is, an 
indolenine nucleus, a benzindolenine nucleus, an indole nucleus, a 
benzoxazole nucleus, a naphthoxazole nucleus, a benzothiazole nucleus, a 
naphthothiazole nucleus, a benzoselenazole nucleus, a benzimidazole 
nucleus, a quinoline nucleus, etc., are appropriate. The carbon atoms of 
these nuclei may also be substituted. 
To merocyanine dyes and complex merocyanine dyes, as nuclei having a 
ketomethylene structure, 5- or 6-membered heterocyclic nuclei such as a 
pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 
2-thiooxazolidin-2,4-dione nucleus, a thiazolidin-2,4-dione nucleus, a 
rhodanine nucleus, a thiobarbituric acid nucleus, etc., may also be 
applicable. 
These sensitizing dyes can be employed individually, and can also be 
employed in combination thereof. A combination of sensitizing dyes is 
often used, particularly for the purpose of supersensitization. 
Representative examples thereof are described in U.S. Pat. Nos. 2,688,545, 
2,977,229, 3,397,060, 3,522,052, 3,527,641, 3,617,293, 3,628,964, 
3,666,480, 3,672,898, 3,679,428, 3,703,377, 3,769,301, 3,814,609, 
3,837,862 and 4,026,707, British Pat. Nos. 1,344,281 and 1,507,803, 
Japanese Patent Publication Nos. 4936/68 and 12375/78, Japanese Patent 
Application (OPI) Nos. 110618/77 and 109925/77, etc. 
The sensitizing dyes may be present in the emulsion together with dyes 
which themselves do not give rise to spectrally sensitizing effects but 
exhibit a supersensitizing effect or materials which do not substantially 
absorb visible light but exhibit a supersensitizing effect. For example, 
aminostilbene compounds substituted with a nitrogen-containing 
heterocyclic group (e.g., those described in U.S. Pat. Nos. 2,933,390 and 
3,635,721), aromatic organic acid-formaldehyde condensates (e.g., those 
described in U.S. Pat. No. 3,743,510), cadmium salts, azaindene compounds, 
etc., can be present. The combinations described in U.S. Pat. Nos. 
3,615,613, 3,615,641, 3,617,295 and 3,635,721 are particularly useful. 
A support used in the light-sensitive material and the dye fixing material 
employed, if desired, according to the present invention is that which can 
endure at the processing temperature. As an ordinary support, not only 
glass, paper, metal or analogues thereof may be used, but also an acetyl 
cellulose film, a cellulose ester film, a polyvinyl acetal film, a 
polystyrene film, a polycarbonate film, a polyethylene terephthalate film, 
and a film related thereto or a plastic material may be used. Further, a 
paper support laminated with a polymer such as polyethylene, etc., can be 
used. The polyesters described in U.S. Pat. Nos. 3,634,089 and 3,725,070 
are preferably used. 
In the photographic light-sensitive material and the dye fixing material of 
the present invention, the photographic emulsion layer and other binder 
layers may contain inorganic or organic hardeners. It is possible to use 
chromium salts (chromium alum, chromium acetate, etc.), aldehydes 
(formaldehyde, glyoxal, glutaraldehyde, etc.), N-methylol compounds 
(dimethylolurea, methylol dimethylhydantoin, etc.), dioxane derivatives 
(2,3-dihydroxydioxane, etc.), active vinyl compounds 
(1,3,5-triacryloyl-hexahydro-s-triazine, 1,3-vinyl-sulfonyl-2-propanol, 
etc.), active halogen compounds (2,4-dichloro-6-hydroxy-s-triazine, etc.), 
mucohalogenic acids (mucochloric acid, mucophenoxychloric acid, etc.), 
etc., which are used individually or as a combination thereof. 
The transfer of dyes from the light-sensitive layer to the dye fixing layer 
can be carried out using a dye transfer assistant. 
The dye transfer assistants suitably used in a process wherein it is 
supplied from the outside include water and an aqueous solution containing 
sodium hydroxide, potassium hydroxide or an inorganic alkali metal salt. 
Further, a solvent having a low boiling point such as methanol, 
N,N-dimethylformamide, acetone, diisobutyl ketone, etc., and a mixture of 
such a solvent having a low boiling point with water or an alkaline 
aqueous solution can be used. The dye transfer assistant may be used by 
wetting the image receiving layer with the transfer assistant. 
When the dye transfer assistant is incorporated into the light-sensitive 
material or the dye fixing material, it is not necessary to supply the 
transfer assistant from the outside. In this case, the above described dye 
transfer assistant may be incorporated into the material in the form of 
water of crystallization or microcapsules or as a precursor which releases 
a solvent at a high temperature. 
More preferred process is a process wherein a hydrophilic thermal solvent 
which is solid at an ambient temperature and melts at a high temperature 
is incorporated into the light-sensitive material or the dye fixing 
material. The hydrophilic thermal solvent can be incorporated either into 
any of the light-sensitive material and the dye fixing material or into 
both of them. Although the solvent can be incorporated into any of the 
emulsion layer, the intermediate layer, the protective layer and the dye 
fixing layer, it is preferred to incorporate it into the dye fixing layer 
and/or adjacent layers thereto. 
Examples of the hydrophilic thermal solvents include ureas, pyridines, 
amides, sulfonamides, imides, alcohols, oximes and other heterocyclic 
compounds. 
The present invention will now be illustrated in greater detail with 
reference to the following examples, but the present invention should not 
be construed as being limited thereto. Unless otherwise indicated, all 
parts, percents, ratios and the like are by weight. 
EXAMPLE 1 
A method of preparing a silver iodobromide emulsion is described in the 
following. 
40 g of gelatin and 26 g of potassium bromide (KBr) were dissolved in 3,000 
ml of water and the solution was maintained at 50.degree. C. with 
stirring. A solution of 34 g of silver nitrate dissolved in 200 ml of 
water was added to the above prepared solution over 10 minutes. Then, a 
solution of 3.3 g of potassium iodide (KI) dissolved in 100 ml of water 
was added over 2 minutes. The thus prepared silver iodobromide emulsion 
was adjusted in pH, precipitated and freed of excess salts. It was then 
ajdusted to pH 6.0, whereby 400 g of a silver iodobromide emulsion was 
obtained. 
A method of preparing a silver benzotriazole emulsion is described in the 
following. 
28 g of gelatin and 13.2 g of benzotriazole were dissolved in 3,000 ml of 
water and the solution was maintained at 40.degree. C. with stirring. A 
solution of 17 g of silver nitrate dissolved in 100 ml of water was added 
to the above prepared solution over 2 minutes. The thus prepared silver 
benzotriazole emulsion was adjusted in pH, precipitated and freed of 
excess salts. It was then adjusted to pH 6.0, whereby 400 g of a silver 
benzotriazole emulsion was obtained. 
A method of preparing a gelatin dispersion of a dye providing substance is 
described in the following. 
A mixture of 5 g of Dye Providing Substance (8) earlier identified, 0.5 g 
of succinic acid 2-ethylhexyl ester sulfonic acid sodium salt, 5 g of 
tricresyl phosphate (TCP) and 30 ml of ethyl acetate was dissolved by 
heating at about 60.degree. C. This solution was mixed with 100 g of a 10% 
aqueous solution of gelatin and the mixture was dispersed by means of a 
homogenizer at 10,000 rpm for 10 minutes. The dispersion thus obtained was 
designated a dispersion of dye providing substance. 
A method of preparing a gelatin dispersion of an acid precursor is 
described in the following. 
5 g of Acid Precursor (1) according to the present invention was added to 
10 ml of a 1% aqueous solution of gelatin and the mixture was ground in a 
mill using 100 g of glass beads having an average diameter of about 0.6 mm 
for 10 minutes. By removing the glass beads by filtration, a gelatin 
dispersion of an acid precursor was obtained. 
In the following, methods of preparing Light-Sensitive Materials A and B 
using the above materials are described. 
______________________________________ 
Light-Sensitive Material A 
______________________________________ 
(a) Silver iodobromide emulsion 
20 g 
(b) Silver benzotriazole emulsion 
10 g 
(c) Dispersion of Dye Providing 
33 g 
substance (8) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR26## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) Solution containing 1.6 g of 
guanidine trichloroacetate (a base 
precursor) dissolved in 16 ml of 
ethanol 
(g) Gelatin dispersion of Acid 
10 ml 
Precursor (1) according to the 
present invention 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material A was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 70 ml 
Light-Sensitive Material B 
(a) Silver iodobromide emulsion 
20 g 
(b) Silver benzotriazole emulsion 
10 g 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR27## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) Solution containing 1.6 g of 
guanidine trichloroacetate (a base 
precursor) dissolved in 16 ml of 
ethanol 
(g) Water 10 ml 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and dried. On the thus 
formed layer, the protective layer was provided in the same manner as 
described for Light-Sensitive Material A. 
A method of preparing an image receiving material having an image receiving 
layer is described in the following. 
10 g of a methyl acrylate/N,N,N-trimethyl-N-vinylbenzylammonium chloride 
(1:1 by mol) copolymer was dissolved in 200 ml of water and then uniformly 
mixed with 100 g of a 10% aqueous solution of lime processed gelatin. The 
resulting mixture was uniformly coated at a wet layer thickness of 90 
.mu.m on a paper support laminated with polyethylene with titanium dioxide 
dispersed therein. The thus produced material was dried and then used as 
an image receiving material. 
Light-Sensitive Materials A and B thus obtained were each imagewise exposed 
for 10 seconds at 2,000 lux using a tungsten lamp and then uniformly 
heated for 30 seconds or 40 seconds on a heat block heated at 140.degree. 
C. 
The image receiving material was soaked in water and then superimposed on 
each of the above heated Light-Sensitive Materials A and B in such a 
manner that their coated layers were in contact with each other. 
After heating for 6 seconds on a heated block maintained at 80.degree. C., 
the image receiving material was separated from the light-sensitive 
material, whereupon a negative magenta color image was obtained in the 
image receiving material. 
Negative image density was measured by means of a Macbeth reflective 
densitometer (RD-519). The results thus obtained are shown in Table 1. 
TABLE 1 
______________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
A (Present 1.97 0.08 2.05 0.10 
Invention) 
B (Comparison) 
2.15 0.15 2.20 0.28 
______________________________________ 
It is apparent from the results shown in Table 1 that the increases in the 
maximum density and minimum density are small even when the developing 
time is extended 10 minutes due to the use of the acid precursor according 
to the present invention. On the contrary, in the comparative sample which 
did not contain the acid precursor, a remarkable increase of fog was 
observed. Therefore, it can be understood that the acid precursor 
according to the present invention has a large effect on stopping 
development. 
EXAMPLE 2 
In this example, cases where a silver benzotriazole emulsion is not used 
are illustrated. 
A method of preparing Light-Sensitive Materials C and D is described in the 
following. 
______________________________________ 
Light-Sensitive Material C 
______________________________________ 
(a) Light-sensitive silver iodobromide 
25 g 
emulsion (the same as described in 
Example 1) 
(b) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(c) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR28## 
(d) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(e) Solution containing 1.5 g of 
guanidine trichloroacetate 
dissolved in 15 ml of ethanol 
(f) Gelatin dispersion of Acid 
10 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
______________________________________ 
The above components (a) to (f) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickneas 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material C was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 70 ml 
Light-Sensitive Material D 
(a) Light-sensitive silver iodobromide 
25 g 
emulsion (the same as described in 
Example 1) 
(b) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(c) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR29## 
(d) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(e) Solution containing 1.5 g of 
guanidine trichloroacetate 
dissolved in 15 ml of ethanol 
(f) Water 10 ml 
______________________________________ 
The above components (a) to (f) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and dried. On the thus 
formed layer, the protective layer was provided in the same manner as 
described for Light-Sensitive Material C. Light-Sensitive Materials C and 
D thus obtained were subjected to the same procedures as described in 
Example 1 and the results shown in Table 2 were obtained. 
TABLE 2 
______________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
C (Present 1.85 0.12 1.95 0.18 
Invention) 
D (Comparison) 
2.00 0.20 2.18 0.37 
______________________________________ 
As is apparent from the results shown in Table 2, a large effect on 
stopping development was obtained by using the acid precursor according to 
the present invention. 
EXAMPLE 3 
Light-Sensitive Materials E to G were prepared in the same manner as 
described for Light-Sensitive Material A of Example 1 except using the 
acid precursors shown in Table 3 below in place of Acid Precursor (1), 
respectively, and subjected to the same procedures as described in Example 
1. The results thus obtained are shown in Table 3. 
TABLE 3 
__________________________________________________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Acid Maximum 
Minimum 
Maximum 
Minimum 
Material Precursor 
Density 
Density 
Density 
Density 
__________________________________________________________________________ 
E (Present Invention) 
(26) 1.90 0.08 1.98 0.12 
F (Present Invention) 
(30) 2.04 0.12 2.15 0.15 
G (Present Invention) 
(38) 2.00 0.10 2.11 0.13 
B (Comparison, same 
None 2.15 0.15 2.20 0.28 
as in Example 1) 
__________________________________________________________________________ 
From the results shown in Table 3 it can be understood that the acid 
precursors according to the present invention exhibit excellent effects on 
stopping development. 
EXAMPLE 4 
Dispersions of dye providing substances were prepared in the same manner as 
described in Example 1 except using the dye providing substances shown in 
Table 4 below in place of Dye Providing Substance (8), respectively. 
______________________________________ 
Dye Providing Substance (5) 
5 g Dispersion (I) 
Dye Providing Substance (7) 
7.5 g Dispersion (II) 
Dye Providing Substance (6) 
5 g Dispersion (III) 
______________________________________ 
Light-Sensitive Materials H, J and L were prepared in the same manner as 
described for Light-Sensitive Material A of Example 1 except using the dye 
providing substances as described above in place of Dye Providing 
Substance (8), respectively. Further, Light-Sensitive Materials I, K and M 
were prepared in the same manner as described for Light-Sensitive Material 
B of Example 1 except using the dye providing substances as described 
above in place of Dye Providing Substance (8), respectively. The 
light-sensitive materials thus obtained were subjected to the same 
procedures as described in Example 1 and the results shown in Table 4 were 
obtained. 
TABLE 4 
__________________________________________________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Dispersion of Dye 
Acid Maximum 
Minimum 
Maximum 
Minimum 
Material Providing Substance 
Precursor 
Density 
Density 
Density 
Density 
__________________________________________________________________________ 
H (Present Invention) 
Dispersion (I) (magenta) 
(1) 1.98 0.14 2.04 0.23 
I (Comparison) 
Dispersion (I) (magenta) 
None 2.25 0.20 2.32 0.42 
J (Present Invention) 
Dispersion (II) (yellow) 
(1) 1.80 0.15 1.92 0.25 
K (Comparison) 
Dispersion (II) (yellow) 
None 1.95 0.22 2.02 0.46 
L (Present Invention) 
Dispersion (III) (cyan) 
(1) 2.04 0.15 2.10 0.21 
M (Comparison) 
Dispersion (III) (cyan) 
None 2.30 0.20 2.34 0.38 
__________________________________________________________________________ 
From the results shown in Table 4 it can be understood that the acid 
precursor according to the present invention exhibits excellent effects on 
stopping development. EXAMPLE 5 
In this example the base precursors as described below were used in place 
of guanidine trichloroacetate in Example 1, respectively. 
______________________________________ 
Base Precursor I: 
##STR30## 
Base Precursor II: 
##STR31## 
Light-Sensitive Material N: 
(a) Silver iodobromide emulsion 
20 g 
(the same as described in 
Example 1) 
(b) Silver benzotriazole emulsion 
10 g 
(the same as described in 
Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR32## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) 8% Water-methanol (1:1 by volume) 
32 ml 
solution of Base Precursor I 
(g) Gelatin dispersion of Acid 
10 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 38 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material N was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 70 ml 
Light-Sensitive Material O: 
(a) Silver iodobromide emulsion (the 
20 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR33## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) 8% Water-methanol (1:1 by volume) 
32 ml 
solution of Base Precursor I 
(g) Water 10 ml 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 38 .mu.m and then dried. On the 
thus formed layer, the protective layer was provided in the same manner as 
described for Light-Sensitive Material N. 
______________________________________ 
Light-Sensitive Material P: 
______________________________________ 
(a) Silver iodobromide emulsion (the 
20 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR34## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) 8% Water-methanol (1:1 by volume) 
32 ml 
of Base Precursor II 
(g) Gelatin dispersion of Acid 
10 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 38 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material P was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 70 ml 
Light-Sensitive Material Q: 
(a) Silver iodobromide emulsion (the 
20 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR35## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) 8% Water-methanol (1:1 by volume) 
32 ml 
solution of Base Precursor II 
(g) Water 10 ml 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 38 .mu.m and then dried. On the 
thus formed layer, the protective layer was provided in the same manner as 
described for Light-Sensitive Material P. 
Light-Sensitive Materials N, O, P and Q thus obtained were subjected to the 
same procedures as described in Example 1 and the results shown in Table 5 
were obtained. 
TABLE 5 
__________________________________________________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Base Acid Maximum 
Minimum 
Maximum 
Minimum 
Material Precursor 
Precursor 
Density 
Density 
Density 
Density 
__________________________________________________________________________ 
N (Present Invention) 
I (1) 1.72 0.08 1.79 0.14 
O (Comparison) 
I None 1.80 0.12 1.92 0.26 
P (Present Invention) 
II (1) 2.00 0.10 2.07 0.18 
Q (Comparison) 
II None 2.15 0.14 2.21 0.32 
__________________________________________________________________________ 
As is apparent from the results shown in Table 5, a large effect on 
stopping development was obtained by using the acid precursor according to 
the present invention. 
EXAMPLE 6 
______________________________________ 
Light-Sensitive Material R: 
______________________________________ 
(a) Silver iodobromide emulsion (the 
20 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR36## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) Solution containing 0.8 g of 
guanidine trichloroacetate (a base 
precursor) dissolved in 8 ml of 
ethanol 
(g) Gelatin dispersion of Acid 
5 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
(h) Water 13 ml 
______________________________________ 
The above components (a) to (h) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material R was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 56 ml 
(c) Solution containing 0.9 g of 
guanidine trichloroacetate 
dissolved in 9 ml of ethanol 
(d) Gelatin dispersion of Acid 
5 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
Light-Sensitive Material S: 
(a) Silver iodobromide emulsion (the 
20 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) Dispersion of Dye Providing 
33 g 
Substance (8) (the same as 
described in Example 1) 
(d) 5% Aqueous solution of a compound 
10 ml 
having the following formula: 
##STR37## 
(e) 10% Aqueous solution of a compound 
4 ml 
having the following formula: 
H.sub.2 NSO.sub.2 N(CH.sub.3).sub.2 
(f) Solution containing 0.8 g of 
guanidine trichloroacetate (a base 
precursor) dissolved in 8 ml of 
ethanol 
(g) Water 18 ml 
______________________________________ 
The above components (a) to (g) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film having a thickness 
of 180 .mu.m at a wet layer thickness of 33 .mu.m and then dried. On the 
thus formed layer, a solution having the following composition was coated 
at a wet layer thickness of 30 .mu.m and dried to form a protective layer, 
whereupon Light-Sensitive Material S was prepared. 
______________________________________ 
(a) 10% Aqueous solution of gelatin 
30 ml 
(b) Water 61 ml 
(c) Solution containing 0.9 g of 
guanidine trichloroacetate 
dissolved in 9 ml of ethanol 
______________________________________ 
Light-Sensitive Materials R and S thus obtained were subjected to the same 
procedures as described in Example 1 and the results shown in Table 6 were 
obtained. 
TABLE 6 
______________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
R (Present 2.02 0.10 2.09 0.14 
Invention) 
S (Comparison) 
2.10 0.12 2.19 0.38 
______________________________________ 
It can be understood from the results shown in Table 6 that the acid 
precursor according to the present invention has a large effect on 
stopping development when it is incorporated into a protective layer of a 
light-sensitive material. 
EXAMPLE 7 
A mixture of 10 g of Dye Providing Substance (16), 0.5 g of succinic acid 
2-ethylhexyl ester sulfonic acid sodium salt, 10 g of tricresyl phosphate 
and 20 .mu.ml of cyclohexanone was dissolved by heating at 60.degree. C. 
to prepare a uniform solution. The solution was mixed with 100 g of a 10% 
aqueous solution of lime processed gelatin by stirring and the mixture was 
dispersed by means of a homogenizer to prepare a dispersion of dye 
providing substance. 
Light-Sensitive Material 701 was prepared in the following manner. 
______________________________________ 
(a) Silver iodobromide emulsion (the 
5.5 g 
same as described in Example 1) 
(b) 10% Aqueous solution of gelatin 
0.5 g 
(c) Dispersion of Dye Providing 
2.5 g 
Substance (16) (described above) 
(d) 10% Ethanol solution of guanidine 
1 ml 
trichloroacetate 
(e) 10% Methanol solution of 2,6- 
0.5 ml 
dichloro-4-aminophenol 
(f) 5% Aqueous solution of a compound 
1 ml 
having the following formula: 
##STR38## 
(g) Gelatin dispersion of Acid 
0.5 g 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
(h) Water 6 ml 
______________________________________ 
The above components (a) to (h) were mixed and dissolved by heating and the 
mixture was coated on a polyethylene terephthalate film at a wet layer 
thickness of 85 .mu.m and dried. On the thus formed layer, a protecting 
layer containing 1.5 g/m.sup.2 of gelatin was provided and dried, 
whereupon Light-Sensitive Material 701 was prepared. 
Light-Sensitive Material 701 thus obtained was subjected to light exposure 
and processing in the same manner as described in Example 1 and the 
results shown in Table 7 were obtained. 
TABLE 7 
______________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
701 1.62 0.09 1.71 0.15 
______________________________________ 
From the results shown in Table 7 it can be recognized that the acid 
precursor according to the present invention also exhibits the remarkable 
effects of the present invention in a light-sensitive material containing 
a dye providing substance which releases a dye upon coupling reaction with 
the oxidation product of a developing agent. 
EXAMPLE 8 
A mixture of 5 g of Dye Providing Substance (17) having the structure shown 
below, 4 g of an electron donor having the structure shown below, 0.5 g of 
succinic acid 2-ethylhexyl ester sulfonic acid sodium salt, 10 g of 
tricresyl phosphate and 20 ml of cyclohexanone was dissolved by heating at 
about 60.degree. C. Then, the same procedure as described in Example 7 was 
carried out to prepare a dispersion of dye providing substance capable of 
being reduced. 
##STR39## 
Light-Sensitive Material 801 was prepared in the same manner as described 
for Light-Sensitive Material 701 in Example 7 except using the above 
described dispersion of dye providing substance capable of being reduced 
in place of the dispersion of Dye Providing Substance (16) and the 
indicated amount of the electron donor. 
Light-Sensitive Material 801 thus obtained was subjected to light exposure 
and processing in the same manner as described in Example 1 and the 
results shown in Table 8 was obtained. 
TABLE 8 
______________________________________ 
Heating at 140.degree. C. 
Heating at 140.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
801 1.50 0.12 1.56 0.19 
______________________________________ 
From the results shown in Table 8 it can be recognized that the acid 
precursor according to the present invention also exhibits good effect in 
a light-sensitive material containing a dye providing substance which is 
capable of being reduced and providing a positive image with respect to a 
silver image. 
EXAMPLE 9 
A method of preparing a gelatin dispersion of a coupler is described in the 
following. 
A mixture of 5 g of 2-dodecylcarbamoyl-1-naphthol (Dye Providing Substance 
(18)), 0.5 g of succinic acid 2-ethylhexyl ester sulfonic acid sodium 
salt, 2.5 g of tricresyl phosphate (TCP) and 30 ml of ethyl acetate was 
dissolved. The solution was mixed with 100 g of a 10% aqueous solution of 
gelatin by stirring and the mixture was dispersed by means of a 
homogenizer at 10,000 rpm for 10 minutes. 
Light-Sensitive Material 901 was prepared in the following manner. 
______________________________________ 
(a) Silver iodobromide emulsion (the 
10 g 
same as described in Example 1) 
(b) Gelatin dispersion of coupler 
3.5 g 
(described above) 
(c) Solution containing 0.25 g of 
guanidine trichloroacetate dissolved 
in 2.5 ml of ethanol 
(d) 10% Aqueous solution of gelatin 
5 g 
(e) Solution containing 0.2 g of 2,6- 
dichloro-p-aminophenol dissolved 
in 15 ml of water 
(f) Gelatin dispersion of Acid 
2 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
______________________________________ 
A coating solution having the composition shown above was coated on a 
polyethylene terephthalate film support at a wet layer thickness of 60 
.mu.m and dried, whereupon Light-Sensitive Material 901 was prepared. 
Light-Sensitive Material 901 thus obtained was imagewise exposed for 5 
seconds at 2,000 lux using a tungsten lamp and then uniformly heated for 
20 seconds or 30 seconds on a heated block heated at 150.degree. C., 
whereupon a negative cyan color image was obtained. 
Negative image density was measured by means of a Macbeth transmission 
densitometer (TD-504). The results thus obtained are shown in Table 9. 
TABLE 9 
______________________________________ 
Heating at 150.degree. C. 
Heating at 150.degree. C. 
for 20 Seconds 
for 30 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
901 1.85 0.18 1.93 0.29 
______________________________________ 
From the results shown in Table 9 it can be understood that the acid 
precursor according to the present invention exhibits a large effect on 
stopping development. 
EXAMPLE 10 
In this example, a black-and-white system is illustrated. 
Light-Sensitive Material 1001 was prepared in the following manner. 
______________________________________ 
(a) Silver iodobromide emulsion (the 
1 g 
same as described in Example 1) 
(b) Silver benzotriazole emulsion (the 
10 g 
same as described in Example 1) 
(c) 10% Ethanol solution of guanidine 
1 ml 
trichloroacetate 
(d) 5% Methanol solution of a compound 
2 ml 
having the following formula: 
##STR40## 
(e) Gelatin dispersion of Acid 
1 ml 
Precursor (1) according to the 
present invention (the same as 
described in Example 1) 
______________________________________ 
A coating solution having the composition shown above was coated on a 
polyethylene terephthalate film support at a wet layer thickness of 60 
.mu.m and dried, whereupon Light-Sensitive Material 1001 was prepared. 
Light-Sensitive Material 1001 thus obtained was imagewise exposed for 5 
seconds at 2,000 lux using a tungsten lamp and then uniformly heated for 
30 seconds or 40 seconds on a heated block heated at 130.degree. C., 
whereupon a negative brown image was obtained. 
Negative image density was measured by means of a Macbeth transmission 
densitometer (TR-504). The results thus obtained are shown in Table 10. 
TABLE 10 
______________________________________ 
Heating at 130.degree. C. 
Heating at 130.degree. C. 
for 30 Seconds 
for 40 Seconds 
Light-Sensitive 
Maximum Minimum Maximum Minimum 
Material Density Density Density Density 
______________________________________ 
1001 0.68 0.12 0.75 0.21 
______________________________________ 
From the results shown in Table 10 it can be understood that the acid 
precursor according to the present invention exhibited the large effect on 
stopping development. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.