Dye-forming developers in an imaging material and process

In a dye-forming imaging material comprising (a) a dye-forming coupler, and (b) an organic reducing agent that is capable in its oxidized form of reacting with the dye-forming coupler to form a dye, improvements are provided by a reducing agent that is a ureidoaniline silver halide developing agent free of strong electron withdrawing groups. Such an imaging material can be a photographic silver halide material. The imaging material can be a photothermographic material for producing a dye image comprising, in reactive association, (a) photographic silver halide, (b) a dye-forming coupler, and (c) an oxidation-reduction image forming combination comprising (1) an organic silver salt oxidizing agent, and (2) an organic reducing agent for the organic silver salt oxidizing agent, wherein the reducing agent is a ureidoaniline which is capable in its oxidized form of reacting with the dye-forming coupler to form a dye. A thermographic material comprises the same combination of components without the need for photographic silver halide. A silver image and dye image are produced in such an exposed photothermographic material by heating the material until the silver image and dye image are produced. An image in a thermographic material is produced by imagewise heating the material. Ureidoaniline silver halide developing agents are also useful in processing compositions for photographic silver halide materials.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a dye-forming material and process for producing 
a dye image by means of a dye-forming coupler and a ureidoaniline 
developing agent that is capable in its oxidized form of reacting with the 
dye-forming coupler. It also relates to a photothermographic material and 
a thermographic material and process for producing a dye image by means of 
such a coupler and developing agent. 
2. Description of the State of the Art 
Dye-forming imaging materials and processes are known for producing dye 
images by means of a dye-forming coupler and a reducing agent that is 
capable in its oxidized form of reacting with the dye-forming coupler. 
Such materials and processes are described in, for example, Research 
Disclosure, December 1978, Item No. 17643. 
Silver halide photothermographic materials and processes for producing 
silver images and dye images are also known. Examples of such materials 
and processes are described in, for instance, U.S. Pat. Nos. 3,531,286 and 
3,761,270. Such photothermographic materials comprise, in reactive 
association, (a) photographic silver halide, (b) a dye-forming coupler and 
(c) an oxidation-reduction image forming combination comprising (1) an 
organic silver salt oxidizing agent and (2) an organic reducing agent for 
the organic silver salt oxidizing agent wherein the organic reducing agent 
in its oxidized form reacts with the dye-forming coupler. 
Phenylenediamine silver halide developing agents have been included in such 
imaging materials as the organic reducing agent. One problem encountered 
with these developing agents is that they do not enable a sufficiently 
wide optimum pH latitude for coating such imaging materials, especially 
such photothermographic materials and for dye formation. Another problem 
centers on the desire to replace the phenylenediamine developing agents 
with milder reducing agents in such photothermographic materials. No 
answer to these problems is found in the photographic art. 
It has been desirable to replace the p-phenylenediamine silver halide 
developing agents in such imaging materials and processes with a milder 
developing agent that enables efficient, dye formation without such 
disadvantages and tendency to produce higher minimum density values than 
desired and that enables a water optimum pH range for coating and for dye 
formation. 
SUMMARY OF THE INVENTION 
It has been found that these problems are answered by a dye-forming imaging 
material, preferably a photographic silver halide material, comprising (a) 
a dye-forming coupler, and (b) an organic reducing agent that is capable 
in its oxidized form of reacting with the dye-forming coupler to form a 
dye, wherein the reducing agent is a ureidoaniline silver halide 
developing agent free of strong electron withdrawing groups. Preferably, 
the dye-forming imaging material is a silver halide photothermographic 
material comprising, in reactive association; 
(a) photographic silver halide, 
(b) a dye-forming coupler, and 
(c) an oxidation-reduction image forming combination comprising 
(1) an organic silver salt oxidizing agent, such as an organic silver salt 
oxidizing agent comprising a silver salt of a long chain fatty acid, and 
(2) an organic reducing agent for said organic silver salt oxidizing agent, 
wherein the reducing agent is a ureidoaniline reducing agent that is 
capable in its oxidized form of reacting with the dye-forming coupler. 
During processing the ureidoaniline reducing agent in its oxidized form 
reacts with the dye-forming coupler to form a dye. A silver image is also 
formed in the exposed photographic material upon processing. 
This is illustrated by the following equations: 
##STR1## 
A further reaction that is believed to take place in a photothermographic 
material in the exposed areas during processing is illustrated by the 
following equation: 
##STR2## 
The ureidoaniline reducing agents are milder reducing agents than 
p-phenylenediamines. They enable a wider pH latitude for coating of a 
photographic material and for dye formation than p-phenylenediamines. 
The terminology "free of strong electron withdrawing groups" herein means 
that the described ureidoaniline silver halide developing agent contains 
no substituent group which has sufficiently high electron withdrawing 
properties to prevent or adversely affect the ureidoaniline silver halide 
developing from producing a dye upon processing. An example of a strong 
electron withdrawing group which is to be avoided is 
##STR3## 
as illustrated in following comparative Example A. 
A process of producing a dye image in an exposed photothermographic element 
according to the invention comprises heating the element to a temperature 
within the range of about 90.degree. C. to about 200.degree. C., 
preferably about 100.degree. C. to about 150.degree. C., until the dye 
image is produced. A silver image is also produced during heating. The dye 
image preferably enhances the silver image. 
A thermographic material according to the invention comprises the same 
components as a photothermographic material without the need for 
photographic silver halide. A process of producing an image in a 
thermographic element according to the invention comprises imagewise 
heating the element to a temperature within the range of about 90.degree. 
to about 200.degree. C. until the image is produced. 
DETAILED DESCRIPTION OF THE INVENTION 
A variety of ureidoaniline silver halide developing agents are useful in an 
imaging element, such as a photothermographic element, a thermographic 
material or a dye-forming processing solution. Combinations of 
ureidoaniline developing agents and other silver halide developing agents 
are useful. Examples of ureidoaniline reducing agents are represented by 
the formula: 
##STR4## 
wherein Z is the atoms, preferably atoms, selected from the group 
consisting of carbon, hydrogen, nitrogen and oxygen atoms to complete an 
aniline silver halide developing agent; 
R.sup.1 is alkyl containing 1 to 25 carbon atoms, such as methyl, ethyl, 
propyl, butyl, decyl, eicosyl, pentacosyl; benzyl, and 
##STR5## 
aryl containing 6 to 25 carbon atoms, such as phenyl, methoxyphenyl, 
3-hydroxy-5-methylphenyl, naphthyl, tolyl and xylyl; or with R.sup.2 is 
the atoms selected from the group consisting of carbon, nitrogen and 
oxygen atoms necessary to complete a 5 or 6 member nonaromatic 
heterocyclic group, such as a pyrrlino, pyrrolidino, piperazino or 
piperidino group; 
R.sup.2 is hydrogen; alkyl containing 1 to 25 carbon atoms, such as methyl, 
ethyl, propyl, butyl, decyl, eicosyl and pentacosyl; aryl containing 6 to 
25 carbon atoms, such as phenyl, naphthyl, tolyl and xylyl; or with 
R.sup.1 is the atoms selected from the group consisting of carbon, 
nitrogen and oxygen atoms necessary to complete a 5 or 6 member 
nonaromatic heterocyclic group; 
R.sup.3 is alkyl containing 1 to 25 carbon atoms, such as methyl, ethyl, 
propyl, butyl, octyl, decyl, eicosyl and pentacosyl, or aryl containing 6 
to 25 carbon atoms such as phenyl, naphthyl, tolyl and xylyl; and 
R.sup.4 is alkylene containing 1 to 25 carbon atoms, such as methylene, 
ethylene and hexadecylene; or arylene containing 6 to 25 carbon atoms, 
such as phenylene, tolylene and xylene. The ureidoaniline silver halide 
developing agents according to the invention are capable, in oxidized 
form, of reaction with a coupler to form a dye. The substituent groups on 
the ureidoaniline silver halide developing agent should not interfere with 
the desired oxidative coupling reaction to form a desired dye. 
The terms "alkyl" and "aryl" herein include unsubstituted alkyl, such as 
unsubstituted methyl, ethyl, propyl or butyl, and unsubstituted aryl, such 
as unsubstituted phenyl. The terms also include alkyl and aryl that are 
substituted by groups which do not adversely affect the desired properties 
of the photographic material, the ureidoaniline silver halide developing 
agent or the coupling reaction which forms a dye. Examples of useful 
substituted alkyl groups include alkyl substituted by alkoxy such as 
methoxy and ethoxy. Substituted alkyl also includes 
##STR6## 
wherein R.sup.4 and R.sup.3 are as defined. Examples of useful substituted 
aryl groups include methoxyphenyl, 2,4,6-triisopropyl-phenyl and tolyl. 
Aryl herein includes alkaryl such as benzyl and xylyl. 
A preferred ureidoaniline silver halide developing agent is represented by 
the formula: 
##STR7## 
wherein R.sup.5 is alkyl containing 1 to 25 carbon atoms, such as methyl, 
ethyl, propyl, butyl, decyl, eicosyl pentacosyl; and, 
##STR8## 
aryl containing 6 to 25 carbon atoms, such as phenyl and naphthyl; or 
with R.sup.6 is the atoms selected from the group consisting of carbon, 
nitrogen and oxygen atoms necessary to complete a 5 or 6 member 
heterocyclic group, such as a pyrrlidino, piperazino or piperidino group; 
R.sup.6 is hydrogen, alkyl containing 1 to 25 carbon atoms, such as methyl, 
ethyl, propyl, butyl, decyl, eicosyl and pentacosyl; or aryl containing 6 
to 25 carbon atoms, such as phenyl and naphthyl; or with R.sup.5 is the 
atoms selected from the group consisting of carbon, nitrogen and oxygen 
atoms necessary to complete a 5 or 6 member heterocyclic group; 
R.sup.7 is alkyl containing 1 to 25 carbon atoms, such as methyl, ethyl, 
propyl, butyl, dodecyl, tricosyl and pentacosyl; or with R.sup.8 is the 
atoms selected from the group consisting of carbon, nitrogen and oxygen 
atoms, necessary to complete a 5 or 6 member nonaromatic heterocyclic 
group, such as a pyrrolino, pyrrolidino, piperazino or piperidino group; 
R.sup.8 is alkyl containing 1 to 25 carbon atoms, such as methyl, ethyl, 
propyl, butyl, octyl, decyl, eicosyl and pentacosyl; or with R.sup.5 is 
the atoms selected from the group consisting of carbon, nitrogen and 
oxygen atoms necessary to complete a 5 or 6 member nonaromatic 
heterocyclic group; 
R.sup.9 is alkyl containing 1 to 25 carbon atoms, such as methyl, ethyl, 
propyl, butyl, octyl, decyl, eicosyl, and pentacosyl; or aryl containing 6 
to 25 carbon atoms, such as phenyl and naphthyl; 
R.sup.10 is alkylene containing 1 to 25 carbon atoms such as methylene and 
ethylene or arylene containing 6 to 25 carbon atoms, such as phenylene; 
and 
X is hydrogen, alkyl containing 1 to 3 carbon atoms, such as methyl, ethyl 
and propyl; alkoxy containing 1 to 3 carbon atoms, such as methoxy, ethoxy 
and propoxy; bromine; chlorine; or iodine. 
The term "nonaromatic" heterocyclic group herein means that the 
heterocyclic group is not completely saturated. The term does not include 
such groups as pyrazino and pyrimidino groups. A nonaromatic heterocyclic 
group herein has no saturation in conjugation with a nitrogen atom. 
An optimum ureidoaniline reducing agent according to the invention will 
depend upon such factors as the desired image, the particular photographic 
material, processing steps and conditions, particular coupler in the 
photographic material, other components in the photographic material or 
processing composition and the particular photographic silver halide in 
the photographic material. Examples of useful ureidoaniline silver halide 
developing agents include the following: 
##STR9## 
The ureidoaniline reducing agents according to the invention are prepared 
by general methods of synthesis known in the organic synthesis art. An 
illustrative method of synthesis is represented by the reaction: 
##STR10## 
wherein R.sup.1, R.sup.7 and R.sup.8 are as defined. Another method of 
synthesis is represented by the following reaction: 
##STR11## 
wherein R.sup.1, R.sup.2, R.sup.7 and R.sup.8 are as defined. These 
methods involve the reaction of an amine with an isocyanate compound. In 
these methods 0.1 mole of the appropriate amine is dissolved in 200 ml of 
a solvent such as 1,2-dimethoxyethane or ethanol. A catalyst, such as 3 
drops of triethylamine, is preferably added and 0.1 mole of the isocyanate 
is added gradually. The temperature of the reaction is controlled at about 
35.degree. C. The reaction is generally complete within 1 to 24 hours as 
indicated by thin layer chromatographic techniques known in the organic 
synthesis art. If on completion of the reaction, the product does not 
precipitate, the solvent is removed at reduced pressure and the product is 
recrystallized. The ureidoaniline reducing agents prepared according to 
these methods are identified by elemental analysis or other analytical 
techniques known in the organic synthesis art. 
Another method for preparation of ureidoanilines according to the invention 
is illustrated by the following reaction: 
##STR12## 
wherein R.sup.1, R.sup.2, R.sup.7, R.sup.8 and X are as defined and 
R.sup.7 is a group that does not adversely affect the ureidoaniline 
compound, such as CH.sub.3 -- or C.sub.2 H.sub.5 --. 
This latter synthesis permits preparation of a ureidoaniline silver halide 
developing agent without the need for isocyanate intermediates. An 
illustrative preparation of this latter synthesis is as follows: a 
solution of 0.015 mole of a p-phenylenediamine thiocarbamate and 0.03 mole 
of the primary or secondary amine are heated in 80 ml of a solvent, 
preferably 1,2-dimethoxyethane, at reflux under a nitrogen atmosphere. The 
reaction is carried out until thin layer chromatography indicates reaction 
completion. The reaction is generally complete within about 48 hours. The 
product is generally purified by purification methods known in the organic 
synthesis art, such as recrystallization from a solvent, such as toluene. 
Mixtures are generally concentrated at reduced pressure and the excess 
amine is washed from the composition with water. The pure ureidoaniline is 
obtained by recrystallization or other purification techniques known in 
the organic synthesis art. 
The thiocarbamate intermediate compound is also prepared by methods known 
in the organic synthesis art. An example of such a preparation is the 
preparation of 4-diethylamino-2-methoxyaniline ethylthiocarbamate: 300 ml 
of diethyl ether and 100 ml of saturated aqueous sodium bicarbonate are 
placed in a separatory funnel; then, 14.0 grams (0.05 mole) of 
diethylamino-2-methoxyaniline dihydrochloride is added and the mixture 
shaken and separated after effervescence subsides. The aqueous sodium 
bicarbonate is extracted once again with ether. The ether extracts are 
combined, dried over anhydrous potassium carbonate, filtered, cooled to 
15.degree. C., and treated with 5 grams (7 ml, 0.05 mole) of 
triethylamine; then gradually 6 grams (5 ml, 0.05 mole) of ethyl 
chlorothiolformate are added. The addition is gradual (over a period of 15 
minutes) with stirring. The mixture is allowed to come to room temperature 
(about 20.degree. C.), stirred for 20 hours, filtered and then 
concentrated at reduced pressure. The desired product has a melting point 
of 74.degree.-75.degree. C. A sample is recrystallized from ethanol-water 
to provide a purified product having a melting point of 
76.degree.-78.degree. C. Other thiocarbamate compounds prepared by similar 
processes include 4-diethylaminoaniline ethylthiocarbamate (melting point 
of 89.degree.-90.degree. C.) and 4-dimethylaminoaniline ethylthiocarbamate 
(melting point 96.degree.-97.degree. C.). 
Generally, the ureidoaniline reducing agents are colorless in a 
photographic material or photographic processing solution prior to 
processing. Some of the ureidoaniline reducing agents have a slight color 
in the photographic material or photographic processing solution. This 
slight color is not considered unacceptable. 
The term "colorless" herein means that the ureidoaniline reducing agent 
does not absorb radiation to an undesired degree in the visible region of 
the electromagnetic spectrum. In some photographic materials the 
ureidoaniline absorbs radiation in certain areas of the electromagnetic 
spectrum which does not adversely affect the desired properties of the 
photographic material or the desired image formed upon processing. 
The imaging materials according to the invention generally comprise a 
photographic component, preferably a photographic silver salt such as 
photographic silver halide. It is essential that the photographic 
component not adversely affect the ureidoaniline reducing agent or the 
imaging process. Examples of useful photographic silver halides are silver 
chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide, 
silver iodide and mixtures thereof. The photographic silver halide is 
generally present in the photographic material in the form of an emulsion 
which is a dispersion of the photographic silver halide in a binder. The 
photographic silver halide is present in a range of grain sizes from 
fine-grain to coarse-grain. The composition containing the photographic 
silver halide is prepared by any of the well-known procedures in the 
photographic art, such as described in Research Disclosure, December 1978, 
Item No. 17643. The photographic silver halide material contains addenda 
commonly present in photographic silver halide materials. The photographic 
silver halide material optionally comprises, for example, chemical 
sensitizers, brighteners, antifoggants, emulsion stabilizers, 
light-absorbing or scattering materials, hardeners, coating aids, 
plasticizers, lubricants and antistatic materials, matting agents, 
development modifiers and other addenda described in Research Disclosure, 
December 1978, Item No. 17643, the disclosure of which is incorporated 
herein by reference. The silver halide can be, for example, a tabular 
grain silver halide. The photographic silver halide can also comprise 
silver halide to produce positive images. 
Photographic materials according to the invention contain a range of 
concentrations of photographic silver halide. An optimum concentration of 
photographic silver halide will depend upon such factors as the desired 
image, processing conditions, particular ureidoaniline silver halide 
developing agent and other components in the photographic material. A 
preferred concentration of photographic silver halide in the photographic 
material is within the range of about 0.1 milligrams to about 10 
milligrams of silver per square decimeter of support. 
The photographic silver halide is generally spectrally sensitized by means 
of spectral sensitizing dyes, such as described in Research Disclosure, 
December 1978, Item No. 17643. Spectral sensitizing dyes which are useful 
in the photographic materials include polymethine sensitizing dyes which 
include the cyanines, merocyanines, complex cyanines and merocyanines 
(including tri-, tetra and polynuclear cyanines and merocyanines), as well 
as oxonols, hemioxonols, styryls, merostyryls and streptocyanines. 
Combinations of spectral sensitizing dyes are useful. 
the photographic silver halide in a photothermographic material according 
to the invention is optionally prepared in situ. The photothermographic 
material, for example, can contain photographic silver halide that is 
prepared in or on one or more of the other components of the 
photothermographic material rather than prepared separate from the 
described components and then admixed with them. Such a method of 
preparing silver halide in situ is described in, for example, U.S. Pat. 
No. 3,457,075, the description of which is incorporated herein by 
reference. 
The ureidoaniline reducing agent according to the invention is in any 
location in the imaging material which produces the desired image. The 
ureidoaniline reducing agent is in a location with respect to the 
photographic silver halide that produces a silver image upon processing. 
If desired, the ureidoaniline reducing agent is in a layer contiguous to 
the layer of the photographic element comprising photographic silver 
halide. The term "in reactive association" herein means that the 
photographic silver halide and the ureidoaniline reducing agent are in a 
location with respect to each other which enables the photographic 
material upon processing to produce a desired image. 
Many silver halide developing agents are useful in combination with the 
ureidoaniline reducing agents for developing an image in a photographic 
material. Silver halide developing agents with which the ureidoaniline 
reducing agents are useful are described in, for example, Research 
Disclosure, December 1978, Item No. 17643 and Research Disclosure, June 
1978, Item No. 17029. Examples of such developing agents include, for 
instance, 3-pyrazolidones, such as 1-phenyl-3-pyrazolidone, 
4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone; sulfonamidophenols, such 
as 2,6-dichloro-4-benzenesulfonamidophenol and 
2,6-dibromo-4-benzenesulfonamidophenol; ascorbic acid developing agents 
such as ascorbic acid and ascorbic acid ketals; aminophenol developing 
agents, such as 2,6-dichloro-4-aminophenol. 
The silver halide developing agent or silver halide developing agent 
combination is useful in a range of concentrations in the photographic 
material. A preferred concentration of developing agent or developing 
agent combination is within the range of about 0.1 to about 10.0 moles of 
developing agent or developing agent combination per mole of photographic 
silver halide in the photographic material. 
The term "developing agent" herein includes compounds which are developing 
agents and developing agent precursors. That is, those compounds are 
included which are not developing agents in the photographic material 
until a condition occurs, such as heating or contact with an activator for 
the photographic material. 
The tone of the image, such as the silver image and the image dye, varies 
depending upon such factors as the silver morphology of the developed 
silver image, covering power of the silver materials, the particular dye 
formed, the particular ureidoaniline reducing agent, processing 
conditions, concentration of components and other materials present in the 
photographic material during imaging. In photothermographic materials that 
provide a brown image, an image dye that is especially useful is one that 
is complementary in hue to the brown-silver image. 
The photographic materials according to the invention preferably comprise a 
binder. Binders are useful alone or in combination in a photographic 
material according to the invention. Useful binders in the photographic 
material include both naturally-occurring substances such as proteins, for 
example, gelatin, gelatin derivatives, cellulose derivatives, 
polysaccharides such as dextran, gum arabic and the like, and synthetic 
materials which are compatible with the ureidoaniline reducing agent and 
other components in the photographic material. Hydrophobic binders are 
useful in the photothermographic materials. Such binders include polymers 
of alkylacrylates and methacrylates, acrylic acid, sulfoalkylacrylates or 
methacrylates and those which have cross-linking sites that facilitate 
hardening or curing. Other useful hydrophobic binders include high 
molecular weight materials and resins such as poly(vinyl butyral), 
cellulose acetate butyrate, poly(methyl methacrylate), polystyrene, 
poly(vinyl chloride), chlorinated rubber, poly(isobutylene), 
butadiene-styrene copolymers, vinyl chloride-vinyl acetate copolymers, 
copolymers of vinyl acetate, vinyl chloride and maleic anhydride and the 
like. It is important that the binder, especially the hydrophobic binder, 
not adversely affect the sensitometric properties of the photographic 
material. Poly(vinyl butyral) is a preferred binder in photothermographic 
silver halide materials. This is available under the trademark "Butvar" 
from the Monsanto Company, U.S.A. 
The photographic elements according to the invention optionally comprise an 
overcoat layer and/or interlayer and/or subbing layer to provide desired 
properties. The overcoat layer, for example, increases resistance to 
abrasion and other markings on the photographic element. The overcoat 
layer, interlayer or subbing layer contain, alone or in combination, 
vehicles and binders that are useful in the layer of the element 
containing the photographic silver halide. 
An imaging element according to the invention comprises a variety of 
supports. Useful supports include those which are resistant to adverse 
changes in structure due to processing conditions and which do not 
adversely affect the desired sensitometric properties of the photographic 
materials. Useful supports include, for example, poly(vinyl acetal), 
poly(ethylene terephthalate) and polycarbonate films, as well as related 
films and resinous materials. Glass, paper, metal and the like supports 
are also useful. A flexible support is generally most useful. 
The photographic materials according to the invention are coated on a 
support by procedures known in the photographic art. Such procedures 
include, for example, immersion or dip coating, roller coating, reverse 
roll coating, air-knife coating, doctor-blade coating, spray coating, 
extrusion coating, dip coating, stretch-flow coating and curtain coating. 
The photographic materials are generally imagewise exposed by means of 
various forms of energy to produce a developable image. Such forms of 
energy include those to which the photographic material is sensitive. 
These forms of energy include the ultraviolet, visible and infrared 
regions of the electromagnetic spectrum, as well as electron beam and beta 
radiation, gamma ray, x-ray, alpha particle, neutron radiation and other 
forms of radiant energy in either non-coherent (random phase) forms or 
coherent (in phase) forms as produced by lasers. Exposures are 
monochromatic, orthochromatic or panchromatic depending upon the spectral 
sensitization of the photographic silver halide. Imagewise exposure is 
generally for a sufficient time and intensity to produce a developable 
image in the photographic material. 
The photothermographic materials are processed after exposure in a single 
step or multistep process to produce a silver image and dye image. In a 
single step process the photothermographic element after exposure is 
heated to processing temperature to produce a silver image and a dye 
image. In a multistep process the initial heating step is sufficient to 
enable development of the exposed photographic silver halide. Subsequent 
steps are then at optionally higher temperatures to enable dye formation 
and optionally to transfer dye to an image receiver. Processing 
temperatures are within the range of about 90.degree. C. to about 
200.degree. C. Preferably, the process is carried out at a processing 
temperature which does not adversely affect the support of the 
photothermographic element. The processing temperature is preferably 
within the range of about 100.degree. C. to about 150.degree. C. 
Heating is carried out during processing until a desired image is produced, 
generally within about 2 to about 90 seconds. Selection of an optimum 
processing time and temperature for each processing step will depend upon 
such factors as the desired image and particular components of the 
photographic material. 
A variety of heating means are useful to heat the photothermographic 
material to develop the desired image. The heating means is, for example, 
a hot plate, iron, roller, heated drum, infrared heating means, hot air 
heating means and the like. 
Processing is preferably carried out under ambient conditions of pressure 
and humidity. Pressures and humidity outside normal atmospheric conditions 
are also useful. 
A variety of organic heavy metal salt oxidizing agents, preferably organic 
silver salt oxidizing agents, are useful in a photothermographic material 
according to the invention. Examples of useful organic silver salt 
oxidizing agents are described in, for example, Research Disclosure, June 
1978, Item No. 17029, the description of which is incorporated herein by 
reference. Examples of useful organic silver salt oxidizing agents include 
silver behenate, silver stearate, silver palmitate and silver salts of 
other compounds such as silver salts of 1,2,4-mercaptotriazole 
derivatives, such as described in Research Disclosure, June 1977, Item No. 
15869. Another class of useful organic silver salt oxidizing agent is 
represented by complexes or salts of silver with a nitrogen acid, such as 
a nitrogen acid selected from the group consisting of imidazole, pyrazole, 
urazole, 1,2,4-triazole and 1H-tetrazole nitrogen acids or combinations of 
these acids. The silver salts or complexes of nitrogen heterocyclic acids 
are described in, for example, Research Disclosure, October 1976, Item No. 
15026. Selection of an optimum organic silver salt or complex oxidizing 
agent, or combination of such oxidizing agents, will depend upon such 
factors as the desired image, particular silver halide, processing 
temperature and other conditions, particular ureidoaniline reducing agent 
and other addenda in the photothermographic material. 
The terms "salt" and "complex" herein include any type of bonding or 
complexing mechanism which enables the resulting material to provide 
desired imaging properties in the photographic materials according to the 
invention. In some instances, the exact bonding of the described organic 
silver salt or complex is not fully understood. The terms "salt" and 
"complex" are intended to include neutral complexes and non-neutral 
complexes. 
A stabilizer or stabilizer precursor is optionally present in the 
photothermographic material to provide improved post-processing image 
stability. It is desirable in most instances to stabilize the silver 
halide after processing to help reduce post-processing printup. A variety 
of stabilizers and stabilizer precursors are useful in the 
photothermographic materials. The stabilizers and stabilizer precursors 
are useful alone or in combination. Optional stabilizers and stabilizer 
precursors are sulfur compounds that form a stable silver mercaptide after 
image development with the photographic silver material at processing 
temperatures. Photolytically active halogenated organic compounds are also 
optionally useful in the photothermographic materials according to the 
invention. Such stabilizers and stabilizer precursors are described in, 
for example, Research Disclosure, June 1978, Item No. 17029, the 
description of which is incorporated herein by reference. Selection of an 
optimum stabilizer or stabilizer precursor or combination thereof will 
depend upon such factors as the particular photographic silver halide, 
processing conditions, desired image, particular ureidoaniline reducing 
agent, and other components in the photothermographic material. 
The photothermographic material according to the invention generally 
comprises an image toner to produce a more neutral appearing or black tone 
image upon processing. Combinations of image toners are also useful. The 
optimum toning agent or toning agent combination will depend upon such 
factors as the particular photographic silver halide, the desired image, 
particular processing conditions, particular ureidoaniline reducing agent 
and other components in the photothermographic material. Useful toning 
agents are selected from those described in, for example, Research 
Disclosure, June 1978, Item No. 17029, the description of which is 
incorporated herein by reference. Preferred toning agents are 
phthalazinone, phthalimide, N-hydroxynaphthalimide, phthalazine, and 
succinimide and combinations of such toning agents. 
A toning agent or toning agent combination is useful in a range of 
concentrations in a photothermographic material according to the 
invention. The optimum concentration of toning agent or toning agent 
combination will depend upon the described factors such as the particular 
photographic silver halide, processing conditions, desired image, 
particular ureidoaniline reducing agent and other components in the 
photothermographic material. A preferred concentration of toning agent or 
toning agent combination is within the range of about 0.01 to about 1.0 
mole of toning agent per mole of organic silver salt oxidizing agent in 
the photothermographic material. 
The photothermographic material can contain a melt-forming compound to aid 
in processing. The melt-forming compound generally provides an improved 
developed image. The term "melt-forming compound" herein means a compound 
which upon heating to the described processing temperature produces an 
improved reaction medium, generally a melt medium, within which the 
image-forming combination and photographic component produce better image 
development. The exact nature of the reaction medium in the 
photothermographic material at processing temperatures is not fully 
understood. It is believed at the reaction temperatures a melt occurs 
which permits the reaction components to better interact and to fuse into 
contiguous layers of the photothermographic element. Useful melt-forming 
compounds are generally components separate from the image-forming 
combination, although the image-forming combination and other addenda in 
the photothermographic material generally enter into the melt formation. 
Preferred melt-forming compounds are amides, imides, cyclic ureas and 
triazoles which are compatible with other components of the 
photothermographic materials and do not adversely affect dye formation. 
Useful melt-forming compounds are generally selected from those described 
in, for example, U.S. Pat. No. 3,438,776. Examples of useful melt-forming 
compounds include 1,3-dimethylurea, N-propylurea, 2-pyrrolidone and 
formamide. Combinations of melt-forming compounds are also useful. 
The melt-forming compound or combination of melt-forming compounds is 
useful in a range of concentrations in the photothermographic materials 
according to the invention. Preferred concentrations of melt-forming 
compounds are within the range of about 0.5 to about 2 parts by weight of 
melt-forming compound per gram of organic silver salt oxidizing agent in 
the photothermographic material. The optimum concentration of the 
melt-forming compound or combination of melt-forming compounds will depend 
upon the described factors. 
A photographic material and/or a photographic processing solution according 
to the invention comprises a dye-forming coupler. Useful dye-forming 
couplers form dyes that absorb in the visible, ultraviolet or infrared 
regions of the electromagnetic spectrum. Such dye-forming couplers are 
described in, for example, Research Disclosure, December 1978, Item No. 
17643 and Research Disclosure, June 1978, Item No. 17029, the description 
of which is incorporated herein by reference. The dye-forming coupler 
optionally has a coupling off group in the coupling position of the 
coupler if desired. This coupling off group is, for example, chloro, 
phenoxy and phenylmercaptotetrazole. Preferred dye-forming couplers are 
two-equivalent couplers or four-equivalent couplers. The term 
"four-equivalent coupler" herein means a dye-forming coupler that requires 
4 moles of silver for each mole of dye formed in the photographic material 
according to the invention. The term "two-equivalent coupler" herein means 
a dye-forming coupler that requires 2 moles of silver for each mole of dye 
formed in the photographic material according to the invention. A 
preferred dye-forming four-equivalent coupler includes a resorcinol 
coupler as described in, for example, U.S. Pat. No. 4,126,461. Examples of 
useful resorcinol dye-forming couplers are 2-acetamido resorcinol and 
2-trifluoroacetamido resorcinol. Other useful dye-forming four-equivalent 
couplers include diacylaminophenol couplers described in U.S. Pat. No. 
2,772,162; couplers containing fluoroalkylcarbonamido groups described in 
U.S. Pat. No. 2,895,826; 1-naphthyl-2-carboxylic acid amide couplers 
described in U.S. Pat. No. 2,474,293; 1-hydroxynaphthamide couplers 
described in U.S. Pat. No. 3,002,836; acylated amino pyrazolone couplers 
described in U.S. Pat. No. 2,369,489; halogen substituted 
1-phenyl-3-acylamino-5-pyrazolone couplers described in U.S. Pat. No. 
2,600,788; couplers containing a phenoxyacylamino group as described in 
U.S. Pat. No. 2,908,573; acetoacetanilide couplers as described in U.S. 
Pat. No. 3,265,506; benzoylacetanilide couplers as described in U.S. Pat. 
No. 2,875,057; and, phenolic dye-forming couplers containing a ureido 
group as described in European Pat. No. 0028099, the disclosures of which 
are incorporated herein by reference. Useful dye-forming two-equivalent 
couplers are listed in, for example, Research Disclosure, December 1978, 
Item No. 17643, paragraph VII; and Research Disclosure, November 1979, 
Item No. 18716. 
The dye-forming coupler is preferably incorporated in the photographic 
element. However, the dye-forming coupler is optionally in a processing 
solution for processing a photographic element according to the invention. 
In preparing a photographic material comprising a ureidoaniline reducing 
agent, a dispersion solvent is optionally present to produce a coating 
composition. A coupler solvent known in the photographic art is optionally 
present for aiding dispersion of the dye-forming coupler and/or the 
ureidoaniline reducing agent. Examples of optional coupler solvents 
include N-n-butylacetanilide, diethyl lauramide, di-n-butyl phthalate and 
2,4-ditertiary amylphenol. The ureidoaniline reducing agent and the 
dye-forming coupler are optionally loaded into a latex, or a non-solvent 
dispersion is prepared if desired. 
The dye-forming coupler is useful in a range of concentrations in the 
photographic materials. Preferred concentrations of dye-forming coupler 
are within the range of about 0.1 to about 10 moles per mole of 
ureidoaniline in the photographic material. The optimum concentration of 
dye-forming coupler or combination of dye-forming couplers in the 
photographic materials will depend upon the described factors. 
The dye-forming coupler or combination of dye-forming couplers are useful 
in a range concentration in a processing solution according to the 
invention. Preferred concentrations of dye-forming coupler or combinations 
of dye-forming couplers in a processing solution are within the range of 
about 0.1 to about 10 moles per mole of ureidoaniline in the photographic 
processing solution. The optimum concentration of dye-forming coupler or 
combination of dye-forming couplers in a processing solution will depend 
upon the described factors. 
A preferred dye-forming coupler in the dye-forming imaging element 
comprises a compound represented by the formula: 
##STR13## 
An optional embodiment of the invention comprises a dye-forming imaging 
composition comprising (a) a dye-forming coupler, and (b) an organic 
reducing agent that is capable in its oxidized form of reacting with the 
dye-forming coupler to form a dye, wherein the reducing agent is a 
ureidoaniline silver halide developing agent. Such a dye-forming imaging 
composition is useful in, for example, a layer of an imaging element 
contiguous to a layer containing photographic silver halide. 
A preferred example of such a dye-forming imaging composition comprises a 
ureidoaniline silver halide developing agent consisting essentially of 
1-(p-diethylaminophenyl)-3-t-butylurea and a dye-forming coupler 
consisting essentially of a compound represented by the formula: 
##STR14## 
Another embodiment of the invention is a thermographic material comprising, 
in reactive association, in binder, (a) a dye-forming coupler, and (b) an 
oxidation-reduction image-forming combination comprising (1) an organic 
silver salt oxidizing agent, and (2) an organic reducing agent for the 
organic silver salt oxidizing agent, wherein the reducing agent is a 
ureidoaniline reducing agent that is capable in its oxidized form of 
reacting with the dye-forming coupler to form a dye. Such a thermographic 
material generally comprises a toning agent, such as described, including 
for example, a toning agent selected from the group consisting of 
phthalazinone, phthalimide, N-hydroxynaphthalimide, phthalazine and 
succinimide toning agents and combinations thereof. 
A preferred thermographic material according to the invention comprises, in 
reactive association, in a poly(vinyl butyral) binder, (a) an 
oxidation-reduction image-forming combination comprising (1) an organic 
silver salt oxidizing agent comprising silver behenate, and (2) an organic 
reducing agent for the organic silver salt oxidizing agent comprising a 
ureidoaniline reducing agent that consists essentially of 
1-(p-diethylaminophenyl)-3-t-butylurea; and, (b) a dye-forming coupler. 
An image is produced in the thermographic material by imagewise heating the 
thermographic material to a temperature within the range of about 
90.degree. C. to about 200.degree. C. until an image is produced. 
A further embodiment of the invention is a dye-forming processing solution 
for a photographic silver halide element wherein the solution comprises 
(a) a dye-forming coupler, (b) a ureidoaniline silver halide developing 
agent that is capable in its oxidized form of reacting with the 
dye-forming coupler to form a dye, (c) an alkaline activator, and (d) at 
least one solvent for the processing solution. 
A variety of solvents are useful for the dye-forming processing solution 
according to the invention. Examples of useful solvents include water and 
methanol. Selection of an optimum solvent for the dye-forming processing 
solution will depend upon the described factors. 
A variety of alkaline activators are useful in the dye-forming processing 
solution. Alkaline activators that are useful are selected from those 
known in the photographic art for processing solution activation. Examples 
of useful alkaline activators include NaOH, Na.sub.3 PO.sub.4, Na.sub.2 
CO.sub.3 and K.sub.2 CO.sub.3. Selection of an optimum alkaline activator 
will depend upon the described factors. 
A preferred photographic processing solution according to the invention 
comprises (a) 1-(p-diethylaminophenyl)-3-hydroxyethylurea as the 
ureidoaniline silver halide developing agent, (b) an activator, such as 
potassium carbonate and (c) a solvent, such as water. The processing 
solution preferably has a pH of at least 10, such as about 10 to about 14. 
Another embodiment of the invention is a method of forming a dye image in 
an exposed photographic element comprising a support bearing, in reactive 
association, (a) photographic silver halide, and (b) a dye-forming 
coupler, comprising developing the exposed photographic element in a 
silver halide developer solution, wherein the developer solution comprises 
an alkaline activator and a ureidoaniline silver halide developing agent 
which reacts in its oxidized form with the dye-forming coupler to form a 
dye. This method of forming a dye image also can comprise bleaching and 
fixing the resulting image. Optimum conditions, such as temperature and 
time of processing, will depend upon the described factors, such as the 
desired image, particular dye-forming coupler, particular ureidoaniline 
silver halide developing agent and siver halide emulsion.

The following examples are included for a further understanding of the 
invention. 
EXAMPLES 1-14 
This illustrates use of ureidoaniline silver halide developing agents with 
a resorcinolic coupler in a photographic material. 
A photographic element was prepared as follows: 
A composition was prepared by adding the following to 0.3 g of 
tetrahydrofuran (solvent): 
______________________________________ 
1(H)--phthalazinone 2.0 mg 
(toner) 
mercuric chloride 0.25 mg 
(antifoggant) 
surfactant 6.0 mg 
(Pluronic L121 which 
is a block copolymer 
of ethylene oxide and 
propylene oxide and 
is a trademark of 
BASF Wyandotte, U.S.A.). 
______________________________________ 
To this composition was added 0.05 mmole of ureidoaniline developing agent 
(listed in following Table IA) and 0.05 mmole of the resorcinolic coupler: 
##STR15## 
Then, the following were added to the resulting composition: 
______________________________________ 
poly(vinylbutyral) (binder) 
0.5 g 
("Butvar B76" which is 
a trademark of and avail- 
able from the Monsanto Co., 
U.S.A.) (5.0% by weight in 
toluene) 
silver behenate dispersion 
0.6 g 
(comprising: 
acetone 406.9 g 
toluene 438.3 g 
poly(vinylbutyral) 55.0 g 
alumina 8.0 g 
behenic acid 31.2 g 
lithium stearate 5.9 g 
silver behenate 50.0 g) 
AgBrI emulsion (0.01 - grains) 
0.2 g 
(prepared by mixing: 
acetone, 
poly(vinylbutyral) 
lithium iodide, anhydrous, 
lithium bromide anhydrous, 
silver trifluoroacetate, to 
produce an emulsion com- 
prising 15.7% solids and 
40 g Ag/liter of solution) 
______________________________________ 
The resulting photothermographic composition was coated at a total silver 
coverage of 0.9 g/M.sup.2 on a poly(ethyleneterephthalate) film support 
containing a subbing layer to produce a photothermographic element. This 
photothermographic element was imagewise exposed to light in a commercial 
sensitometer for 10.sup.-3 seconds through a 0.3 log E step tablet to 
produce a developable latent image in the photothermographic element. The 
latent image was developed by uniformly heating the photothermographic 
element for ten seconds at 125.degree. C. The heating was carried out by 
placing the side of the element opposite the exposed photothermographic 
layer on a vapor-heated processing drum. A dye image and silver image were 
produced in each photothermographic element containing a ureidoaniline as 
listed in following Table IA. 
TABLE IA 
______________________________________ 
##STR16## 
Ex- D.sub.max (to 
am- red light) 
ple R.sup.7 
(dye image 
No. R.sup.5 R.sup.6 and R.sup.8 
only) 
______________________________________ 
1 H 
##STR17## CH.sub.3 
0.16 
##STR18## H CH.sub.3 
0.55 
3 
##STR19## H CH.sub.3 
0.40 
4 
##STR20## H CH.sub.3 
0.30 
5 CH.sub.2 CH.sub.2 OH 
CH.sub. 2 CH.sub.2 OH 
CH.sub.3 
0.55 
6 
##STR21## H CH.sub.3 
0.25 
7 
##STR22## H C.sub.2 H.sub.5 
0.24 
8 
##STR23## H C.sub.2 H.sub.5 
0.29 
9 
##STR24## H C.sub.2 H.sub.5 
0.28 
10 CH.sub.2 CH.sub.2 OH 
CH.sub.2 CH.sub.2 OH 
C.sub.2 H.sub.5 
0.46 
11 
##STR25## C.sub.2 H.sub.5 
0.69 
12 
##STR26## C.sub.2 H.sub.5 
0.72 
13 
##STR27## C.sub.2 H.sub.5 
1.58 
14 
##STR28## 
##STR29## C.sub.2 H.sub.5 
1.79 
______________________________________ 
The dye images were tested for Examples 10, 13 and 14 for stability in the 
dark. This test consisted of storing processed samples in a dark drawer 
under ambient conditions for the specified time and then re-measuring dye 
densities. The dye image of Example 10 faded 50% in one week. The dye 
image of Example 13 faded 10% in three weeks. The dye image of Example 14 
faded 10% in one week. 
EXAMPLES 15-26 
This illustrates use of ureidoaniline silver halide developing agents with 
a naphtholic dye-forming coupler in a photographic material. 
The procedure described in Example 1 is repeated with the exceptions that 
(1) the dye-forming coupler in Example 1 was replaced by the following 
dye-forming coupler: 
##STR30## 
and (2) the ureidoaniline silver halide developing agents listed in 
following Table IIA replaced the ureidoaniline silver halide developing 
agents of Examples 1-14. 
TABLE IIA 
______________________________________ 
##STR31## 
Exam- D.sub.max (to red 
ple R.sup.7 
light) (dye 
No. R.sup.5 R.sup.6 and R.sup.8 
image only) 
______________________________________ 
15 
##STR32## 
##STR33## 
C.sub.2 H.sub.5 
.ltoreq.0.2 
16 
##STR34## H C.sub.2 H.sub.5 
0.56 
17 (CH.sub.2).sub.2 OH 
H C.sub.2 H.sub.5 
0.9 
18 (CH.sub.2).sub.3 OH 
H C.sub.2 H.sub.5 
0.9 
19 
##STR35## H C.sub.2 H.sub. 5 
0.63 
20 n-butyl H C.sub.2 H.sub.5 
0.78 
21 n-hexyl H C.sub.2 H.sub.4 
0.90 
22 n-octyl H C.sub.2 H.sub.5 
0.90 
23 n-dodecyl H C.sub.2 H.sub.5 
1.15 
24 cyclohexyl H C.sub.2 H.sub.5 
1.03 
25 t-butyl H C.sub.2 H.sub.5 
1.46 
26 
##STR36## H C.sub.2 H.sub.5 
1.1 
______________________________________ 
EXAMPLE 27 
This illustrates use of a dye image to enhance a silver image in a 
photographic element according to the invention. 
The procedure described in Example 14 was repeated. A dye and silver image 
was produced. The maximum and minimum density observed by red light and 
the contrast of the images were as follows: 
______________________________________ 
D.sub.max 
D.sub.min 
Contrast* 
______________________________________ 
Ag image only 
1.22 0.06 0.7 
Ag image plus 
2.96 0.12 4.0 
dye image 
______________________________________ 
*Contrast herein is measured for the straightline portion if the 
sensitometric curve. 
This demonstrates that the dye image significantly enhances the silver 
image and significantly increases contrast. 
EXAMPLE 28 
This further illustrates use of a dye image to enhance a silver image in a 
photographic element according to the invention. The procedure described 
in Example 25 was repeated. A dye and silver image was produced. The 
maximum and minimum density observed by red light and the contrast of the 
images were as follows: 
______________________________________ 
D.sub.max 
D.sub.min 
Contrast 
______________________________________ 
Ag image only 
0.82 0.09 0.5 
Ag image plus 
2.26 0.10 6.0 
dye image 
______________________________________ 
This demonstrates that the dye image significantly enhances the silver 
image and significantly increases contrast. 
EXAMPLES 29-35 
The procedure described in Example 1 was repeated with the exception that 
developing agent of Example 25: 
##STR37## 
and the dye-forming couplers listed in the following Table IIIA 
respectively replaced the ureidoaniline silver halide developing agent and 
the dye-forming coupler of Example 1. 
TABLE IIIA 
__________________________________________________________________________ 
D.sub.max 
Example (to red light) 
No. Dye-Forming Coupler (dye only) 
__________________________________________________________________________ 
29 
##STR38## 0.51 
30 
##STR39## 1.1 
31 
##STR40## 0.76 
32 
##STR41## 1.09 
33 
##STR42## 2.27 
Example D.sub.max 
No. Dye-Forming Coupler (dye only) 
__________________________________________________________________________ 
34 
##STR43## 0.12 (to blue light) 
35 
##STR44## 0.58 (to blue 
__________________________________________________________________________ 
light) 
Cyan dye was formed with both the four equivalent coupler of Example 29 and 
the two equivalent coupler of Example 30. The coupler of Example 33 was 
preferred due to the maximum density of the dye image produced compared to 
the dye images produced with other couplers listed in Table IIIA. 
EXAMPLE 36 
The procedure described in Example 33 was repeated in which the 
ureidoaniline silver halide developing agent was the developing agent of 
Example 25: 
##STR45## 
and the dye-forming coupler was the dye-forming coupler of Example 33: 
##STR46## 
A silver image and dye image were produced. The maximum density, minimum 
density observed by red light and contrast of these images were as 
follows: 
______________________________________ 
Dmax Dmin Contrast 
______________________________________ 
Ag image only 
0.74 0.02 0.5 
Ag image plus 
3.00 0.16 7.0 
dye image 
______________________________________ 
EXAMPLE 37 
This illustrates formation of a magenta dye. The procedure described in 
Example 1 was repeated with the exception that the following ureidoaniline 
silver halide developing agent replaced the developing agent of Example 1: 
##STR47## 
and the following dye-forming coupler replaced the dye-forming coupler of 
Example 1: 
##STR48## 
This combination of ureidoaniline silver halide developing agent and 
dye-forming coupler produced a magenta dye image upon oxidative coupling. 
EXAMPLES 38-40 
This illustrates use of a ureidoaniline silver halide developing agent in a 
silver halide developer solution. 
A photographic silver halide element was prepared by coating on a 
poly(ethyleneterephthalate) film support a layer comprising (a) 
photographic silver chloride (150 mg/ft.sup.2 as Ag corresponding to 1610 
mg/M.sup.2) spectrally sensitized to the red region of the electromagnetic 
spectrum by means of a spectral sensitizing dye, (b) a dye-forming coupler 
consisting of 
##STR49## 
(55 mg/ft.sup.2 corresponding to 590 mg/M.sup.2) in a gelatin binder (350 
mg/ft.sup.2 corresponding to 3763 mg/M.sup.2). The photographic element 
contained a gelatin overcoat (82 mg/ft.sup.2 of gelatin corresponding to 
880 mg/M.sup.2). The photographic silver chloride element was imagewise 
exposed to light (2850.degree. K. color temperature) by means of a 
commercial sensitometer for 1/50 second through a Wratten 29 filter 
(Wratten is a trademark), a 0.9 neutral density filter and a step tablet 
to produce a developable latent image in the element. The exposed 
photographic element was developed by immersing the element for 20 minutes 
at 38.degree. C. in a silver halide developer solution containing: 
______________________________________ 
1-(p-diethylaminophenyl)- 
1 g. 
3-hydroxyethylurea 
(ureidoaniline silver 
halide developing agent) 
potassium carbonate 2 g. 
(activator) 
water to make 1 liter 
(pH adjusted to 11.0 at room 
temperature (20.degree. C.)) 
______________________________________ 
The developed photographic element was then immersed in an aqueous stop 
bath comprising 3% by weight acetic acid for one minute. The silver image 
developed and unreacted silver chloride were bleached in a bleach solution 
and fixed in a fixing solution to reveal a cyan dye image. 
Very faint dye images were produced by repeating the procedure with the 
exception that the 1-(p-diethylaminophenyl)-3-hydroxyethylurea was 
replaced respectively by 0.7 g/liter of Example 39 
##STR50## 
and 1.06 g/liter of Example 40 
##STR51## 
Examples A-K are comparative examples. 
EXAMPLE A 
The procedure described in Example 15 was repeated with the exception that 
the ureidoaniline silver halide developing agent in Example 15 was 
replaced by the following ureidoaniline compound: 
##STR52## 
No dye image was observed in the processed photothermographic element. 
This indicates that strong electron withdrawing groups, such as 
##STR53## 
on the ureido moiety adversely affect dye formation. 
EXAMPLES B-J 
The procedure described in Example 1 was repeated with the exception that 
the developer of Example 25: 
##STR54## 
and the dye-forming couplers listed in the following Table IVA 
respectively replaced the ureidoaniline silver halide developing agent and 
the dye-forming coupler of Example 1. None of the photothermographic 
elements formed a dye image observable by the light noted in Table IVA. 
No attempt was made to change or optimize the concentrations of components 
and processing conditions to produce a dye image observable by red or 
green light in these examples. 
TABLE IVA 
__________________________________________________________________________ 
Exam- 
ple No. 
Dye-Forming Coupler Dmax 
__________________________________________________________________________ 
##STR55## 0 (to red light) 
C 
##STR56## 0 (to green 
light) 
D 
##STR57## 0 (to green 
light) 
E 
##STR58## 0 (to green 
light) 
F 
##STR59## 0 (to green 
light) 
G 
##STR60## 0 (to green 
light) 
H 
##STR61## 0 (to green 
light) 
I 
##STR62## 0 (to green 
light) 
J 
##STR63## 0 (to green 
__________________________________________________________________________ 
light) 
.cndot. in the formulas herein means a carbon atom with any free bonds 
being satisfied by hydrogen atoms. 
Ph in the formulas herein means phenyl. 
Bu in the formulas herein means butyl. 
Et in the formulas herein means ethyl. 
EXAMPLE K 
A photothermographic element was prepared by mixing and coating the 
following composition at a 101.6 micron (4 mil) wet coating thickness on a 
poly(ethyleneterephthalate) film support: 
In 0.2 g of 2-methoxyethanol with 0.1 g tetrahydrofuran and 0.4 g of 
toluene were dissolved 
______________________________________ 
dye-forming coupler 28 mg 
of Example 33 
phthalazinone 2 mg 
(toner) 
HgCl.sub.2 0.125 mg 
1-(p-diethylaminophenyl)- 
11 mg 
3-t-butylurea 
(developing agent) 
______________________________________ 
0.14 g of 7 weight percent poly(vinylbutyral) (binder) (Butvar B-76 which 
is a trademark of and available from the Monsanto Co., U.S.A.) in toluene 
were added to the resulting composition with 0.6 g of silver behenate 
dispersion from Example 1 and 0.2 g of the silver bromoiodide emulsion 
from Example 1. The resulting photothermographic material was permitted to 
dry for five minutes at 54.degree. C. 
The photothermographic element was then imagewise exposed to light by means 
of a commercial sensitometer through a step tablet to produce a 
developable latent image in the element. The exposed photothermographic 
element was heated for 15 seconds at 120.degree. C. on a heated metal 
block. This produced a silver image and dye image. The maximum density of 
the dye image (observed by red light) was 1.87. The minimum density of the 
dye image was 0.06. 
The procedure was repeated with the exception that (1) the ureidoaniline 
silver halide developing agent was replaced by 7 mg. of a 
para-phenylenediamine silver halide developing agent consisting of 
##STR64## 
(2) the phthalazinone was omitted and (3) the exposed element was heated 
for ten seconds. This provided a purple dye image having a maximum density 
(observed by green light) of 0.85 and a minimum density of 0.12. The 
reason for omitting phthalazinone was that otherwise fog would have been 
excessive. The dye density of the image was significantly lower than the 
dye density of the image produced in the photothermographic element 
containing the ureidoaniline silver halide developing agent. 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention.