Photographic image recording method using silver halide and vinyl monomer

A method for recording a photographic image on an image-recording material is provided, wherein an image-recording material formed by coating at least a photographic silver halide, a polymerizable vinyl monomer, and a hydrazine derivative represented by formula (I) ##STR1## wherein X represents a hydrogen atom, an alkyl group, or a group represented by ##STR2## positioned in an ortho-, meta-, or para-position on the benzene ring; Y represents ##STR3## or --SO.sub.2 --; R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represents a hydrogen atom, an unsubstituted alkyl group, or a substituted alkyl group, provided that R.sub.1 represents a hydrogen atom only when Y represents ##STR4## on a support is imagewise exposed to form a latent image in said photographic silver halide and then heated so as to polymerize said polymerizable vinyl monomer in the part having said latent image to form a polymer image therein. The present process does not require any wet treatment, and is capable of forming a polymer image simply by heating for a short period of time, and thus, may record a polymer image with a photo-sensitivity which is comparable to that of a conventional silver halide photographic material, with the use of only a small amount of silver halide.

FIELD OF THE INVENTION 
The present invention relates to a method for recording photographic 
images, and more particularly to a method for formation of a polymer image 
on a photographic material wherein polymerizable monomers are polymerized 
in the presence of silver halide in a dry-system treatment. 
BACKGROUND OF THE INVENTION 
Techniques for forming a polymer image by photo-polymerization in which an 
organic dye is used as a photo-sensitizer (photo-polymerization initiator) 
are well known, but the sensitivity thereof is generally ISO 10.sup.-3 or 
less (ISO: International Organization for Standardization), which is far 
inferior to the sensitivity of silver halide photographic materials. 
Various methods have heretofore been tried in which a silver halide is 
used as a trigger and the high amplification degree thereof in a 
development procedure is utilized for initiation of the polymerization 
reaction. For instance, Japanese Patent Publication Nos. 46-6581 and 
46-16357, Japanese Patent Application (OPI) Nos. 57-138632, 57-142638, 
57-176033, 58-107529, 58-169143, and 58-174947 (the term "OPI" as used 
herein refers to a "published unexamined Japanese patent application"), 
and U.S. Pat. Nos. 3,707,379, 3,767,400, 3,782,943, 3,697,275, 3,756,818, 
3,687,667, 3,874,947, 3,756,820 and 3,746,542 describe a polymerization 
method in which the polymerization reaction is initiated by a radical 
derived from a reducing agent oxidized during development of silver 
halide. Japanese Patent Publication No. 41-18862 (corresponding to U.S. 
Pat. No. 3,241,962) describes a polymerization method in which a 
polymerization reaction is initiated by a radical derived from a peroxide, 
due to the redox reaction of a silver image obtained by development of a 
silver halide and a peroxide. Japanese Patent Publication No. 39-2657 
(corresponding to U.S. Pat. No. 3,345,164) describes a polymerization 
method in which the polymerization reaction is initiated by a radical 
derived from a peroxide, due to the redox reaction of a silver ion as 
remaining in a non-exposed part and dissolved out therefrom, after 
development of a silver halide, and a peroxide. U.S. Pat. No. 3,029,145 
describes a polymerization method in which the polymerization reaction is 
initiated by a radical derived from a peroxide, due to the redox reaction 
of an iron(I)-salt remaining in a non-exposed part, after development of a 
silver halide with an iron(I)-salt, and a peroxide. Japanese Patent 
Application (OPI) No. 55-149939 (corresponding to U.S. Pat. No. 4,287,290) 
describes a polymerization method in which the polymerization reaction is 
directly initiated by a reducing agent remaining in a non-exposed part, 
after development of a silver halide. 
In these methods, monomers are polymerized in the presence of a radical 
generated directly or after post-treatment from any of raw materials 
(silver halide or reducing agent) or products (silver image or 
oxidation-product of reducing agent) as participated in the development of 
a silver halide. It is assumed that a polymer image is formed with a 
sensitivity similar to a silver halide in said methods; however, such 
methods have the disadvantage that a wet treatment is required in every 
development of silver halide and polymerization in the presence of a 
radical. Also, in methods using a peroxide, deterioration of recording 
materials and occurrence of fog are usually significant during the 
dark-polymerization to be carried out in the presence of a radical formed 
by decomposition of said peroxide. In addition, the polymerization 
reaction requires, in general, a long time period. 
SUMMARY OF THE INVENTION 
The object of the present invention is to overcome the disadvantages and 
defects in the prior art and to provide a novel photographic image 
recording method, which does not require any wet treatment, but which 
rather can form a polymer image by only heating for a short period of 
time. Thus, the present novel method may record a polymer image with a 
photo-sensitivity which is comparable to that of a conventional silver 
halide photographic material, using only a small amount of silver halide. 
The present inventors have now found that a good polymer image of high 
sensitivity may be formed by only heating for a short period of time when 
a specific hydrazine derivative is used as a developing agent of a silver 
halide and a polymerization initiator. 
Accordingly, the present invention provides a method for recording a 
photographic image on an image-recording material, wherein an 
image-recording material formed by coating at least a photographic silver 
halide, a polymerizable vinyl monomer, and a hydrazine derivative 
represented by formula (I) 
##STR5## 
wherein X represents a hydrogen atom, an alkyl group, or a group 
represented by 
##STR6## 
positioned in an ortho-, meta- or para-position on the benzene ring; Y 
represents 
##STR7## 
or --SO.sub.2 --; R.sub.1, R.sub.2, R.sub.3, and R.sub.4 each represents a 
hydrogen atom, an unsubstituted alkyl group, or a substituted alkyl group, 
provided that R.sub.1 represents hydrogen atom only when Y represents 
##STR8## 
on a support is imagewise exposed to form a latent image in said 
photographic silver halide and then heated so as to polymerize said 
polymerizable vinyl monomer in the part having said latent image to form a 
polymer image therein. 
In the hydrazine derivative of formula (I), X is preferably 
##STR9## 
positioned in an ortho- or para-position of the benzene ring. 
DETAILED DESCRIPTION OF THE INVENTION 
The image recording material to be used in the present invention basically 
has a photographic layer comprising a photographic silver halide, a 
polymerizable vinyl monomer, the above-described hydrazine derivative, 
and, in general, an additional binder polymer, coated on a support. Said 
photographic layer may be a single layer or otherwise, may comprise two or 
more adjacent layers, and each layer may freely contain the 
above-described components. Accordingly, a photographic silver 
halide-containing layer and a polymerizable vinyl monomer-containing layer 
are provided on a support and said hydrazine derivative may be 
incorporated in either of said layers; or alternatively, a separate layer 
containing said hydrazine derivative only may be provided. The order of 
these layers to be coated on the support is not specifically limitative. 
In view of cost, a single layer is preferred. 
Said photographic layer may further contain, in order to enhance the 
polymerization reaction efficiency, various kinds of an organic silver 
salt-oxidizing agent, a base or base precursor, and a hot-melting solvent, 
as described below in detail. Moreover, in case the formed polymer image 
is required to be made visible, some substance, e.g., coloring agent such 
as a dye, a pigment, a dye precursor, etc. which is necessary therefor may 
be incorporated in the photographic layer of the present invention, as 
hereunder described in detail. 
A characteristic feature of the present invention is to use the hydrazine 
derivatives of formula (I), which are selected from .beta.-acyl-p(or 
-o)-amino(or -monoalkylamino, or -dialkylamino)phenylhydrazines, 
.beta.-acyl-p(or -o)-alkoxyphenylhydrazines, .beta.-alkylsulfonyl-p(or 
-o)-amino(or -monoalkylamino, or -dialkylamino)phenylhydrazines, 
.beta.-alkylsulfonyl-p(or -o)-alkoxyphenylhydrazines, .beta.-acyl-p(or 
-o)-alkylphenylhydrazines, and .beta.-acyl-phenylhydrazines. 
In the formula (I), when R.sub.1 through R.sub.4 represent an unsubstituted 
alkyl group or a substituted alkyl group, said alkyl group may be either 
linear or branched and have from 1 to 18 carbon atoms, preferably from 1 
to 5 carbon atoms. Examples of alkyl groups are a methyl group, an ethyl 
group, an n-propyl group, an isopropyl group, an n-butyl group, an 
iso-butyl group, a tert-butyl group, an n-amyl group, an iso-amyl group, a 
tert-amyl group, etc. Examples of substituents of said alkyl groups are a 
hydroxyl group, a chlorine, or bromine atom, an alkoxy group having from 1 
to 5 carbon atoms, a phenyl group, a substituted phenyl group (which is 
substituted in any of o-, m-, or p-position by a substituent of a chlorine 
or bromine atom or an alkyl group having from 1 to 5 carbon atoms, or an 
alkoxy group having from 1 to 5 carbon atoms), an acyl group having from 1 
to 5 carbon atoms, etc. 
Examples of preferred compounds are as follows: .beta.-acetyl-p(or 
-o)-aminophenylhydrazine, .beta.-formyl-p(or -o)-aminophenylhydrazine, 
.beta.-propionyl-p(or -o)-aminophenylhydrazine, .beta.-butyryl-p(or 
-o)-aminophenylhydrazine, .beta.-isobutyryl-p(or -o)-aminophenylhydrazine, 
.beta.-chloroacetyl-p(or -o)-aminophenylhydrazine, .beta.-acetyl-p(or 
-o)-N-methylaminophenylhydrazine, .beta.acetyl-p(or 
-o)-N,N-dimethylaminophenylhydrazine, .beta.-acetyl-p(or 
-o)-N,N-diethylaminophenylhydrazine, .beta.-formyl-p(or 
-o)-N,N-dimethylaminophenylhydrazine, .beta.-propionyl-p(or 
-o)-N,N-dimethylaminophenylhydrazine, .beta.-acetyl-p(or 
-o)-methoxyphenylhydrazine, .beta.-acetyl-p(or -o)-ethoxyphenylhydrazine, 
.beta.-formyl-p(or -o)-methoxyphenylhydrazine, .beta.-methylsulfonyl-p(or 
-o)-aminophenylhydrazine, .beta.-methylsulfonyl-p(or 
-o)-methoxyphenylhydrazine, .beta.-acetylphenylhydrazine, 
.beta.-propionylphenylhydrazine, .beta.-formylphenylhydrazine, 
.beta.-chloroacetylphenylhydrazine, 
.beta.-hydroxypropionylphenylhydrazine, .beta.-methoxyacetylphenylhydrazin 
e, .beta.-acetyl-p-tolylhydrazine, .beta.-formyl-p-tolylhydrazine, 
.beta.-acetyl-o-tolylhydrazine, 
.beta.-1,1-dihydroxymethylpropionyl-p-tolylhydrazine, 
.beta.-trihydroxymethylacetyl-p-tolylhydrazine, 
.beta.-chloroacetyl-p-ethylphenylhydrazine, etc. 
Photographic silver halides to be used in the present invention are those 
obtained in conventional means, including silver chloride, silver 
bromochloride, silver iodochloride, silver bromide, silver bromoiodide, 
silver bromoiodochloride, and silver iodide. The particle size of said 
silver halide is generally within the range of from 0.001 .mu.m to 10 
.mu.m, preferably from 0.001 .mu.m to 2 .mu.m. Silver halides may be 
chemically sensitized, for example, with a chemical sensitizer such as 
sulfur, selenium, tellurium, gold, platinum, palladium, rhodium, iridium, 
or with a reducing agent for a silver halide. In addition, these may 
optionally be spectral-sensitized in a conventional manner. Such means are 
described in detail in the technical literature, such as T. H. James, The 
Theory of the Photographic Process, 4th Edition, Macmillan Publishing Co., 
Inc., 1977; etc. 
Such spectral-sensitization is advantageous for enhancement of the 
sensitivity of photographic silver halides or for selection of the 
photographic wavelength range. 
Dyes which may be used therefor include methine dyes, cyanine dyes, 
merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, 
holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. 
Especially useful dyes are cyanine dyes, merocyanine dyes, and complex 
merocyanine dyes. Any and every basic heterocyclic nucleus which is 
generally used in cyanine dyes may be applied to said dyes. For instance, 
the following nuclei may be applied thereto: pyrroline nucleus, oxazoline 
nucleus, thiazoline nucleus, pyrrole nucleus, oxazole nucleus, thiazole 
nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, 
pyridine nucleus, etc.; alicyclic hydrocarbon ring-fused nuclei of said 
nuclei: and aromatic hydrocarbon ring-fused nuclei of said nuclei, such as 
indolenine nucleus, benzindolenine nucleus, indole nucleus, benzoxazole 
nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole 
nucleus, benzoselenazole nucleus, benzimidazole nucleus, quinoline 
nucleus, etc. These nuclei may be substituted on their carbon atoms. 
To merocyanine dyes or complex merocyanine dyes may be applied a 
ketomethylene structure-containing nucleus such as pyrazolin-5-one 
nucleus, thiohydantoin nucleus, 2-thiooxazolidine-2,4-dione nucleus, 
thiazolidine-2,4-dione nucleus, rhodanine nucleus, thiobarbituric acid 
nucleus, or the like 5- or 6-membered heterocyclic nucleus. 
These sensitizer dyes may be used singly or in the form of a combination of 
two or more thereof, and the combination of sensitizer dyes is often used, 
especially for the purpose of super-sensitization. 
Other dyes which per se do not have any spectral-sensitization activity or 
some other substances which do not substantially absorb any visible ray 
but have a supersensitization activity, may be incorporated in the 
emulsion, together with said sensitizing dyes. For instance, 
nitrogen-containing heterocyclic ring-substituted aminostyryl compounds 
(for example, those as descried in U.S. Pat. Nos. 2,933,390 and 
3,635,721), aromatic organic acid/formaldehyde condensation products (for 
example, those as described in U.S. Pat. No. 3,743,510), cadmium salts, 
azaindene compounds, etc. may be incorporated in the emulsion. In 
particular, the combinations as described in U.S. Pat. Nos. 3,615,613, 
3,615,641, 3,617,295 and 3,635,721 are preferred. 
The recording materials of the present invention may contain, together with 
a photographic silver halide, an organic silver salt-oxidizing agent, for 
the purpose of oxidizing a reducing agent in the part where a latent image 
is to be formed when heated. These silver salts are relatively stable to 
light, but when heated in the presence of a silver halide having a latent 
image, these may oxidize a reducing agent and themselves are reduced to 
silver. Examples of said silver salts are silver salts of a fatty acid 
(such as behenic acid, stearic acid, lauric acid, maleic acid, adipic 
acid, etc.), an aromatic carboxylic acid (such as benzoic acid, phthalic 
acid, terephthalic acid, salicylic acid, etc.), a mercapto group- or 
thione group-containing compound (such as 
3-mercapto-4-phenyl-1,2,4-triazole, 2-mercaptobenzimidazole, etc.) or an 
imino group-containing compound (such as benzotriazole or derivatives 
thereof as described in Japanese Patent Publication Nos. 44-30270 
(corresponding to British Pat. No. 1,173,426) and 45-18416 (corresponding 
to U.S. Pat. No. 3,635,719), etc.). 
Polymerizable vinyl monomers which may be used in the present invention are 
compounds which have at least one vinyl group or vinylidene group and 
which may be radical-polymerized; and conventional known esters of acrylic 
acid or methacrylic acid, metal salts of acrylic acid (such as barium 
acrylate, calcium acrylate), acrylamide, N,N-methylenebis-acrylamide, 
vinyl-ethers, N-vinyl compounds (such as N-vinylcarbazole), vinyl 
acetates, etc., may be used. Esters of acrylic acid or methacrylic acid 
are especially preferred in the present invention, among them. Examples of 
said monomers are mentioned below, in terms of esters of acrylic acid. 
(Compounds in which one or more acryloyl groups are replaced by the 
methacryloyl groups are also able to be used in the present invention.) 
Monoacrylates such as methyl acrylate, ethyl acrylate or butyl acrylate; 
diacrylates such as polyethyleneglycol diacrylate, polypropyleneglycol 
diacrylate, hexanediol diacrylate, glycerin diacrylate, trimethylolpropane 
diacrylate, pentaerythritol diacrylate; tri- and tetra-acrylates such as 
trimethylolpropane triacrylate, pentaerythritol triacrylate, 
pentaerythritol tetraacrylate; and other various polymerizable 
prepolymers, for example, oligomers obtained by reaction of a hydroxyl 
residue of a polyester and acrylic acid, said polyester being formed by 
condensation of a poly-basic acid (such as phthalic acid, isophthalic 
acid, terephthalic acid, maleic acid, fumaric acid, malonic acid, succinic 
acid, adipic acid, etc.) and a polyhydric alcohol (such as ethyleneglycol, 
propyleneglycol, polyethyleneglycol, polypropyleneglycol, glycerin, 
trimethylolpropane, trimethylolethane, pentaerythritol, etc.), or in other 
words, polyester-acrylates (or oligo-ester-acrylates), as described in 
Japanese Patent Publication No. 52-7361, and epoxy-acrylates and 
polyurethane-acrylates obtained by reaction of a hydroxyl group-containing 
acrylate and an isocyanate, as described in Japanese Patent Publication 
No. 48-41708. 
Two or more monomers may be used together in the method of the present 
invention. 
The coating layer to be provided on the image-recording material used in 
the present invention preferably contain a binder polymer. Examples of 
said binder polymers are water-soluble polymers such as gelatin, 
polyvinylalcohol, polyvinyl-pyrrolidone, carboxymethyl-cellulose, gum 
arabic, casein and methyl-cellulose, and organic solvent-soluble polymers 
such as polymethyl methacrylate, polyvinyl chloride, vinylidene 
chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile 
copolymer, polyvinyl acetate, vinyl acetate-vinyl chloride copolymer, 
styreneacrylonitrile copolymer, polyesters, ABS resin, polyamides, 
chlorinated polyethylene, chlorinated polypropylene, polyvinyl-butyral, 
polyvinylformal and acetyl-cellulose. Solvents to be used for dissolving 
and coating said polymers are water, acetone, toluene, methylene chloride, 
methylene dichloride, chloroform, methylethylketone, ethyl acetate, methyl 
acetate, dimethylformamide, dimethylsulfoxide, etc. 
Said binder polymers may be used singly or in the form of a combination of 
two or more kinds thereof. For instance, a silver halide is prepared in 
the form of a gelatin-emulsion, which may be added to a coating solution 
comprising a binder other than gelatin and a monomer, and the 
thus-prepared coating solution may be coated on the image recording 
material of the present invention. In this case, the mixture comprising 
two or more binders is not necessarily blended uniformly. In addition, the 
monomer is not also necessarily blended uniformly with the binder. For 
example, a water-insoluble monomer may be dispersed in an aqueous solution 
of a water-soluble binder or may non-uniformly dispersed therein in the 
form of micro-capsules. 
The hydrazine derivatives of formula (I) is dissolved or dispersed in water 
or an organic solvent which is compatible with the solvent of the binder, 
and then may be added to the coating solution. 
The photographic layer of the present invention may contain, if desired, a 
base or a base precursor capable of forming a base under heat, for the 
purpose of accelerating the development of silver halides and organic 
silver salt-oxidizing agents. 
Examples of preferred bases are inorganic bases such as alkali metal or 
alkaline earth metal hydroxides, secondary or tertiary phosphates, 
borates, carbonates, quinolinates, metaborates; ammonium hydroxides; 
quaternary alkylammonium hydroxides, and other metal hydroxides; and 
organic bases such as aliphatic amines (e.g., trialkylamines, 
hydroxylamines, aliphatic polyamides); aromatic amines (e.g., 
N-alkyl-substituted aromatic amines, N-hydroxyalkyl-substituted aromatic 
amines and bis [p-(dialkylamino)phenyl]methanes); heterocyclic amines, 
amidines (including cyclic amines), guanidine (including cyclic 
guanidines), etc. Among them, those having a pKa value of 8 or more are 
especially preferred. 
In case a base is to be incorporated in the photographic material, it is 
preferred that said base be added to said material in the form of a 
precursor thereof. 
As base precursors, those capable of releasing a base through some reaction 
under heat are preferably used, including a salt of an organic acid and a 
base capable of decarboxylating and decomposing under heat or a compound 
capable of decomposing and releasing an amine due to the intramolecular 
nucleophilic substitution-reaction, Lossen rearrangement, Beckmann 
rearrangement, or like reaction. Examples of preferred base precursors are 
salts of trichloro-acetic acid, as described in British Pat. No. 998,949; 
salts of .alpha.-sulfonyl-acetic acid as described in U.S. Pat. No. 
4,060,420; salts of propiolic acid as described in Japanese Patent 
Application No. 58-55700; 2-carboxy-carboxamide derivatives as described 
in U.S. Pat. No. 4,088,496; salts of pyrolytic acids, in which an alkali 
metal or alkaline earth metal component is used besides an organic base, 
as a base component, as described in Japanese Patent Application (OPI) No. 
59-195237 (corresponding to European Patent Publication No. 125521A); 
hydroxamine-carbamates as described in Japanese Patent Application (OPI) 
No. 59-168440 (corresponding to European Patent Publication No. 120661A), 
in which Lossen rearrangement is utilized; aldoxime-carbamates capable of 
forming nitrile under heat, as described in Japanese Patent Application 
(OPI) No. 59-157637 (corresponding to European Patent Publication No. 
118078A), etc. In addition, other base precursors as described in British 
Pat. No. 998,945, U.S. Pat. No. 3,220,846, Japanese Patent Application 
(OPI) No. 50-22625 (corresponding to British Pat. No. 1,470,451), and 
British Pat. No. 2,079,480 are also useful. 
Specific examples of base precursors which are especially useful in the 
present invention include guanidine trichloro-acetate, methylguanidine 
trichloro-acetate, potassium trichloro-acetate, guanidine 
phenylsulfonyl-acetate, guanidine p-chlorophenylsulfonyl-acetate, 
guanidine p-methanesulfonylphenyl-sulfonylacetate, potassium 
phenyl-propiolate, cesium phenyl-propiolate, guanidine phenyl-propiolate, 
guanidine p-chlorophenyl-propiolate, guanidine 
2,4-dichlorophenyl-propiolate, guanidine p-phenylene-bis-propiolate, 
tetramethylammonium phenylsulfonyl-acetate, tetramethylammonium 
phenyl-propiolate. 
These base precursors may be used singly or in the form of a mixture of two 
or more thereof. 
The photographic layer may further contain, optionally and rather 
preferably, a hot-melting solvent, for the purpose of accelerating the 
heat-development of the silver halide and the organic silver 
salt-oxidizing agent contained therein and also accelerating the 
polymerization reaction of polymerizable monomers contained therein, and 
in general, incorporation of such hot-melting solvent in the photographic 
layer is preferred. Hot-melting solvents include substances having a 
melting point in the temperature of the heat-development, for example, 
within the range of 80.degree. C. to 200.degree. C., and dissolving the 
hydrazine derivatives of formula (I), when molten, or softening the 
photographic layer, so as to accelerate the movement of said derivative, 
and in addition, said hot-melting solvents can hardly react with silver 
salts, monomers, and hydrazine derivatives. These solvents may be selected 
from organic or inorganic compounds of an extremely broad range, and 
concrete examples thereof are polyhydroxy-compounds such as sorbitol, 
pentaerythritol, trimethylol-propane, trimethylol-ethane, hexane-diol, 
cyclohexane-diol and, saponin, urea, dimethylurea, acetamide, 
N-methylacetamide, etc. 
The image recording material of the present invention may additionally 
contain a reducing agent represented by formula (IIa) or formula (IIb), 
whereby the polymerization speed of the polymerizable monomers contained 
in said material may be enhanced. 
##STR10## 
In the above formulae, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 each 
represents a hydrogen atom, an unsubstituted alkyl group, a substituted 
alkyl group, or an aryl group; Z.sub.1 through Z.sub.8 each represents a 
hydrogen atom, an unsubstituted alkyl group, a substituted alkyl group, an 
alkoxy group, a halogen atom, or an aryl group; and the position of each 
of the R.sub.5 O-- group and R.sub.6 O-- group on the benzene ring may be 
any of ortho-, meta-, or para-position. 
In the reducing agents of formula (IIa), R.sub.7 and R.sub.8 preferably 
represent hydrogen atoms. 
The reducing agents to be used in the present invention are represented by 
formulae (IIa) and (IIb), and substituents therein are explained below in 
greater detail. The alkyl part in the unsubstituted alkyl group and 
substituted alkyl group of said formulae may be either linear or branched 
and have from 1 to 8 carbon atoms, preferably from 1 to 5 carbon atoms. 
Examples of said alkyl groups are methyl group, ethyl group, n-propyl 
group, isopropyl group, n-butyl group, iso-butyl group, tert-butyl group, 
n-amyl group, iso-amyl group, tert-amyl group, etc. Examples of 
substituents of said alkyl groups are a hydroxyl group, a chlorine or 
bromine atom, an alkoxy group having from 1 to 18 carbon atoms, preferably 
from 1 to 5 carbon atoms, an unsubstituted phenyl group, a substituted 
phenyl group (which is substituted in any of o-, m-, or p-position by a 
substituent of a chlorine or bromine atom or an alkyl group having from 1 
to 5 carbon atoms, or an alkoxy group having from 1 to 5 carbon atoms), an 
acyl group having from 1 to 18 carbon atoms, preferably from 1 to 5 carbon 
atoms, etc. Aryl groups include an unsubstituted phenyl group and a 
substituted phenyl group (which is substituted in any of the o-, m-, or 
p-positions by a substituent of a chlorine or bromine atom or an alkyl 
group having from 1 to 5 carbon atoms, or an alkoxy group having from 1 to 
5 carbon atoms). Alkoxy groups are those having an alkyl group which has 
from 1 to 18 carbon atoms, and preferably from 1 to 5 carbon atoms. 
Examples of halogen atoms include chlorine, bromine, fluorine and iodine 
atoms. 
Specific examples of preferred reducing agents are as follows: 
p-aminophenol, m-aminophenol, o-aminophenol, 2,6-dichloro-p-aminophenol, 
2,6-dibromo-p-aminophenol, 2,6-dimethyl-p-aminophenol, 
3,5-dimethyl-p-aminophenol, 2-phenyl-p-aminophenol, 
2-chloro-p-aminophenol, 2,6-dimethoxy-p-aminophenol, 
2,3,6-trimethyl-p-aminophenol, 2,3,5-trimethyl-p-aminophenol, 
3,6-dimethyl-p-aminophenol, 3-methoxy-p-aminophenol, 
3,5-dimethoxy-p-aminophenol, 4-chloro-5-methyl-o-aminophenol, o-(or m- or 
p-)anisole, catechol, resorcinol, 2-methylresorcinol, orcinol, 
hydroquinone, methylhydroquinone, p-(or m- or 0-)methoxyphenol, 
p-benzyloxyphenol, p-ethoxyphenol, 2-methyl-p-methoxyphenol, etc. 
The photographic layer of the present invention may further contain, in 
addition to the above components, known additives such as a preservative, 
an anti-fogging agent, etc., and furthermore, an antihalation layer, an 
antistatic layer, or a protective layer may additionally be provided on 
the image recording material of the present invention. 
Supports that may be used include paper, resin-coated paper, film such as 
polyethylene terephthalate or triacetyl-cellulose, or an aluminium plate, 
and these may appropriately be selected in accordance with the object and 
the use of the recording materials. 
The amount of each of the components constituting the photographic 
materials as mentioned above is as follows: 
The amount of the photographic silver halide to be used is from 0.001 to 
0.5 g, preferably from 0.005 to 0.1 g, per 1 g of the polymerizable vinyl 
monomer as used. The organic silver salt-oxidizing agent is from 0 to 20 
moles, preferably from 0 to 5 moles, per one mole of said silver halide. 
The hydrazine derivative is from 0.1 to 20 moles, preferably from 0.5 to 5 
moles, per one mole of the total silver salt (including the organic silver 
salt-oxidizing agent, if used). The binder polymer is from 0 to 10 g, 
preferably from 0 to 2 g; the base or base precursor is from 0 to 3 g, 
preferably from 0 to 1 g; the hot-melting solvent is from 0 to 3 g, 
preferably from 0 to 1 g; and the reducing agent of formula (IIa) or (IIb) 
is from 0.1 to 20 moles, preferably from 0.5 to 5 moles, per one mole of 
the total silver salt (including the organic silver salt-oxidizing agent, 
if used). 
The dry film thickness of the photographic layer may widely vary, depending 
upon the use and the object of the recording materials. For instance, in 
case the recording material is used for general image recording or 
lithographic printing, said thickness is from 0.1 to 50 .mu.m, preferably 
from 0.5 to 10 .mu.m; or in case said material is used for letterpress 
printing or relief printing where a relief itself is used, said thickness 
is from 1 .mu.m to 5 mm, preferably from 0.1 to 3 mm. 
In the case the development of a silver salt and/or the polymerization of a 
polymerizable monomer in the present recording material is(are) inhibited 
by oxygen in air, it is preferred to provide an oxygen-preventive layer 
composed of a substance having a low oxygen-permeability (such as 
polyvinyl alcohol, gelatin, or copolymer of vinylidene chloride and vinyl 
chloride or acrylonitrile, etc.) on the surface of the photographic layer. 
The film thickness of said oxygen-preventive layer is from 0 to 20 .mu.m, 
preferably from 0 to 5 .mu.m. In case this oxygen-preventive layer is 
coated, this may act also as a protective layer. 
Image recording is carried out, according to the method of the present 
invention, by imagewise exposure of the above-mentioned image-recording 
material followed by uniform heating of the exposed material, whereby a 
polymer is formed on said material in the form of an image. 
The image-exposure may be carried out by the use of a light source 
containing a wavelength to which the photographic silver halide (including 
a spectral-sensitized one) contained in the recording material is 
sensitive, for example, tungsten lamp, halogen lamp, mercury lamp, 
fluorescent lamp, xenon lamp, laser, LED (Light Emittiing Diode), CRT 
(Cathode Ray Tube), etc., whereupon the visible ray or the ultraviolet ray 
in said light source is utilized. In addition, X-ray or electron rays may 
be used for the image-exposure. The exposure varies, depending upon the 
sensitivity of the slver halide used, and is in general, from 10.sup.-2 to 
10.sup.3 ergs/cm.sup.2. Heating may be carried out by the use of a hot 
plate, heat roller, infrared lamp, oil bath or high frequency induction 
heating device, with or without the recording material in contact with 
said heating means. Apart from this, a heat-providing element such as 
carbon black is incorporated in the recording material, which element is 
electrically charged to generate Joule's heat therein, whereby said 
recording material may be heated. The heating temperature is generally 
within the range of from 80.degree. C. to 200.degree. C., and preferably 
from 100.degree. C. to 130.degree. C., and the heating time is generally 
within the range of from 1 to 300 seconds, preferably from 5 to 60 
seconds. In case oxygen in air inhibits the polymerization reaction and/or 
the development of a silver salt in the recording material, a plastic film 
or the like is preferably provided closely on the photographic layer upon 
heating. 
The polymer thus formed in the form of an image as above is converted to a 
visible image or is developed by means of various methods in accordance 
with the use and the object of the recording material, to finally obtain 
the desired image, and the final image is utilized accordingly. For 
instance, if the recording material is used as a printing plate or a 
relief, it may be developed with a solvent. Solvents which may be used for 
said purpose are those which do not dissolve the polymer image part, but 
which do dissolve the other non-hardened part. For instance, in case a 
water-soluble polymer such as polyvinyl alcohol is used as a binder, the 
material may be developed with water. In this case, a dye or a pigment 
which does not desensitize or hardly desensitizes a silver halide is 
preferably incorporated previously in the photographic layer, whereby a 
visible image may be directly formed by solvent-development. On the other 
hand, the formed polymer image may be converted to a visible image by 
means of a dry treatment only. As described in Japanese Patent Publication 
No. 53-40537, for example, the polymerized part and the non-polymerized 
part may be separated to different two sheets by peel-apart development, 
utilizing the difference of the adhesiveness between said polymerized part 
and the non-polymerized part. (In order to make the formed image visible, 
the photographic layer is previously colored, as described above.) In 
addition, the material may be treated with a toner (coloring powder) so 
that the toner can adhere only to the non-polymerized part to form a 
visible image. 
Moreover, coloration or dye-bleaching reaction may be controlled by means 
of a polymer, whereby the polymer image may be converted to a visible one. 
For instance, various conventional means may be utilized therefor, 
including a method where a two-component type heat-sensitive coloring 
material is used and the two components therein move, react and color 
under heat, whereupon the coloration is controlled by the use of an 
imagewise polymer acting as a barrier (that is, the non-hardened part is 
colored in this method), as described in Japanese Patent Application (OPI) 
No. 52-89915; a method where a two-component type coloring material is 
separated to be inside and outside of monomer-containing microcapsules, 
and after polymerization, this is developed under pressure so that 
non-hardened capsules may be crushed and that the material may be colored, 
as described in Japanese Patent Application (OPI) Nos. 57-179836 and 
57-197538; a method where a polymer image is used as a barrier to control 
the bleaching of a dye (that is, the non-hardened part is bleached in this 
method), as described in Japanese Patent Application No. 59-241487; and a 
method where a dye is bleached with a non-polymerized monomer, as 
described in Japanese Patent Application No. 59-222717. 
In case any of said methods for formation of visible image is utilized in 
the present invention, substances which are necessary in the utilized 
method may be added to the photographic layer of the recording material of 
the present invention. 
The mechanism for formation of a polymer image in the method of the present 
invention has not been fully clarified yet, but it is believed that the 
hydrazine derivative of formula (I) acts to reduce the silver halide 
having a latent image or the adjacent organic silver salt-oxidizing agent 
(or develop the silver salt) under heat and said hydrazine derivative 
itself is oxidized to form a radical and the polymerization of the 
co-existing monomer is initiated by said radical. 
The present invention may be utlized in various uses. For instance, the 
recording material of the present invention may be used for a printing 
plate, a proof, a photographic paper, a photographic material for film, a 
hard copy for video signal, a facsimile recording material, a CRT 
recording material, a copying material, an OHP film, etc. In any uses, the 
recording materials of the present invention have various merits over 
conventional materials, as follows: The sensitivity of the prsent 
materials are far higher than that of conventional non-silver-type 
recording materials, and in case a dry treatment system is used in the 
conversion of the polymer image to a visible one, the desired image may be 
recorded on the material only by dry-treatment. As compared with 
conventional silver salt-type photographic materials, the amount of silver 
used is extremely reduced in the present recording materials, whereas the 
sensitivity of the present materials is virtually the same as that of 
conventional materials, and, in addition, the present material may form an 
image by means of a dry-treatment. Thus, the recording materials of the 
present invention have various advantageous over conventional materials.

The present invention is explained in greater detail by reference to the 
following examples, which, however, do not at all restrict the scope of 
the present invention. 
EXAMPLE 1 
A mixture solution comprising: 
Pentaerythritol tetraacrylate (monomer): 1.8 g 
Phthalocyanine: 0.2 g 
Methylene chloride: 2.0 g 
8 wt% aqueous solution of polyvinyl alcohol (average polymerization degree: 
about 500): 12.0 g 
5 wt% aqueous solution of sodium p-dodecylbenzene-sulfonate: 0.5 g 
was emulsified for one hour in an ultrasonic emulsifier, to obtain a 
monomer emulsion. 
6.6 g of benzotriazole and 14 g of gelatin were dissolved in 1500 ml of 
water, and, while stirring at 40.degree. C., a solution of 8.5 g of silver 
nitrate dissolved in 50 ml of water was added thereto over the course of 2 
minutes, and then the pH value of the resulting solution was adjusted to 
about 4-5 with NaOH to precipitate the silver benzotriazole. Unnecessary 
salts (NaNO.sub.3) were removed from said solution, and finally, the pH 
value thereof was adjusted to 6.0, and thus, a silver benzotriazole 
emulsion (yield: 200 g) was obtained. 
A coating solution was prepared from the following components and was 
coated on a film, as mentioned below: 
Monomer emulsion: 10.0 g 
Silver bromochloride emulsion (containing 10 wt% of silver bromochloride, 
in which the molar ratio of chlorine/bromine was 1/1, and 7 wt% of 
gelatin): 0.3 g 
Silver benzotriazole emulsion: 1.2 g 
.beta.-Acetyl-p-aminophenylhydrazine: 0.08 g 
Sorbitol: 0.36 g 
Water: 2.5 g 
Said solution was coated and dried on a polyethylene terephthalate film in 
a dry film thickness of about 5 .mu.m, to obtain an image recording 
material. The coated silver amount was about 0.08 g/m.sup.2. 
The image recording material was exposed to a halogen lamp of 50 lux for 5 
seconds, through a black and white step wedge (optical density step: 0.3), 
and then a polyethylene terephthalate film was closely adhered to the 
surface of the photographic layer of said material and heated with a hot 
plate at 125.degree. C. for 60 seconds. Next, the film was peeled off, and 
the material was dipped in hot water of about 60.degree. C. and warmed for 
30 seconds, while being shaken, whereby the non-exposed part in the 
photographic layer dissolved out into water, and thus, a negative-type 
blue image comprising sharp eight-stage steps (eight steps) was formed on 
the material. 
EXAMPLE 2 
In the same manner as in the Example 1, with the exception that the silver 
benzotriazole emulsion was not added, an image recording material was 
formed and developed. As the result, a blue image of seven-stage steps 
having a slightly lower image density than that of Example 1 was obtained. 
EXAMPLE 3 
In the same manner as in the Example 1, with the exception that the same 
amount of Aronix M-8030.sup.RTM (polyfunctional polyester-acrylate, made 
by Toa Gosei Chemical Industry Co., Ltd.) was used instead of the 
pentaerythritoltetraacrylate, a blue image of nine-stage steps was formed. 
EXAMPLE 4 
In the same manner as in the Example 1, with the exception that the same 
amount of .beta.-formyl-p-aminophenylhydrazine was used instead of the 
.beta.-acetyl-p-aminophenylhydrazine, a blue image of seven-stage steps 
was formed. 
EXAMPLE 5 
In the same manner as in the Example 1, with the exception that the same 
amount of .beta.-formyl-p-methoxyphenylhydrazine was used instead of the 
.beta.-acetyl-p-aminophenylhydrazine and that 0.36 g of guanidine 
tri-acetate was added to the coating solution, a blue image of eight-stage 
steps was formed. 
EXAMPLES 6 TO 11 
A mixture solution comprising: 
Pentaerythritol tetraacrylate: 1.8 g 
Phthalocyanine: 0.2 g 
Methylene chloride: 2.0 g 
8 wt% aqueous solution of polyvinyl alcohol (average polymerization degree: 
about 500): 12.0 g 
5 wt% aqueous solution of sodium p-dodecylbenzene-sulfonate: 0.5 g 
was emulsified for one hour in an ultrasonic emulsifier, to obtain a 
monomer emulsion. 
6.6 g of benzotriazole and 14 g of gelatin were dissolved in 1500 ml of 
water, and, while stirring at 40.degree. C., a solution of 8.5 g of silver 
nitrate dissolved in 50 ml of water was added thereto in the course of 2 
minutes, and then the pH value of the resulting solution was adjusted to 
about 4-5 with NaOH to precipitate the silver benzotriazole. Unnecessary 
salts (NaNO.sub.3) were removed from said solution, and the pH value 
thereof was adjusted to 6.0, and thus, a silver benzotriazole emulsion was 
obtained. Yield: 200 g. 
A coating solution was prepared from the following components and was 
coated on a film, as mentioned below: 
Monomer emulsion: 10.0 g 
Silver bromochloride emulsion (containing 10 wt% of silver bromochloride, 
in which the molar ratio of chlorine/bromine was 1/1, and 7 wt% of 
gelatin): 0.3 g 
Silver benzotriazole emulsion: 1.2 g 
.beta.-acetylphenylhydrazine: 0.15 g 
Reducing agent as listed in the following Table 1: 0.1 g 
Sorbitol: 0.36 g 
Guanidine tri-acetate: 0.36 g 
Water: 2.5 g 
Said solution was coated and dried on a polyethylene terephthalate film in 
a dry film thickness of about 5 .mu.m, to obtain an image recording 
material. The coated silver amount was about 0.08 g/m.sup.2. 
TABLE 1 
______________________________________ 
Example No. Reducing Agent 
______________________________________ 
6 p-methoxyphenol 
7 o-methoxyphenol 
8 hydroquinone 
9 2-methylresorcinol 
10 m-N,N--dimethylaminophenol 
11 p-methoxyaniline 
______________________________________ 
Each of the image recording materials thus obtained was exposed to a 
halogen lamp of 50 lux for 5 seconds, through a black and white step wedge 
(optical density step: 0.3), and then a polyethylene terephthalate film 
was closely adhered to the surface of the photographic layer of said 
material and heated with a hot plate at 125.degree. C. for 40 seconds. 
Next, the film was peeled off, and the material was dipped in hot water of 
about 60.degree. C. and warmed for 60 seconds, while being shaken, 
whereby the non-exposed part in the photographic layer dissolved out into 
water. As a result, a negative-type blue image comprising six to 
seven-stage steps was obtained on each of the materials containing said 
reducing agent. 
EXAMPLES 12 TO 14 
In the same manner as in the Example 6 (where p-methoxyphenol was used as a 
reducing agent), with the exception that the same amount of a hydrazine 
derivative as listed in the following Table 2 was used instead of the 
.beta.-acetylphenylhydrazine, a similar image as in the Example 6 was 
formed on each of the formed recording materials containing each of the 
following hydrazine derivatives. 
TABLE 2 
______________________________________ 
Example No. 
Hydrazine Derivative 
______________________________________ 
12 .beta.-formyl-p-tolylhydrazine 
13 .beta.-1,1-dimethylolpropionyl-p-tolylhydrazine 
14 .beta.-trimethylolacetyl-p-tolylhydrazine 
______________________________________ 
EXAMPLE 15 
A mixture solution comprising: 
Pentaerythritol tetraacrylate: 2.3 g 
Phthalocyanine: 0.1 g 
Methylene chloride: 3.0 g 
8 wt% aqueous solution of polyvinyl alcohol (average polymerization degree: 
about 500): 18.0 g 
5 wt% aqueous solution of sodium p-dodecylbenzene-sulfonate: 0.8 g 
was emulsified for one hour in an ultrasonic emulsifier, to obtain a 
monomer emulsion. 
6.6 g of benzotriazole and 14 g of gelatin were dissolved in 1500 ml of 
water, and, while stirred at 40.degree. C., a solution of 8.5 g of silver 
nitrate dissolved in 50 ml of water was added thereto in the course of 2 
minutes, and then, the pH value of the resulting solution was adjusted to 
about 4-5 with NaOH to precipitate the silver benzotriazole. Unnecessary 
salts (NaNO.sub.3) were removed from said solution, and finally, the pH 
value thereof was adjusted to 6.0, and thus, a silver benzotriazole 
emulsion was obtained. Yield: 200 g. 
A coating solution was prepared from the following components and was 
coated on a film, as mentioned below: 
Monomer emulsion: 2.4 g 
Silver bromochloride emulsion (containing 10 wt% of silver bromochloride, 
in which the molar ratio of chlorine/bromine was 1/1, and 7 wt% of 
gelatin): 0.08 g 
Silver benzotriazole emulsion: 0.32 g 
Hydrazine derivative as listed in the following Table 3: (amount as 
mentioned in said Table) 
Reducing agent as listed in Table 3: (amount as mentioned in said Table) 
Sorbitol: 0.08 g 
Water: 0.64 g 
Said solution was coated and dried on a polyethylene terephthalate film in 
a dry film thickness of about 5 .mu.m, to obtain an image recording 
material. The coated silver amount was about 0.1 g/m.sup.2. 
A half of each of the image recording materials thus obtained was covered 
with a black paper and the other half thereof was not, and these were 
exposed to a halogen lamp of 50 lux for 5 seconds, and then a polyethylene 
terephthalate film was closely adhered to the surface of the photographic 
layer of each material and heated with a hot plate at 125.degree. C. for a 
predetermined period of time. Next, the film was peeled off from the 
photographic layer, and the image recording material was dipped in hot 
water of about 60.degree. C. and warmed for 30 seconds, while being 
shaken, whereby the nonexposed part in the photographic layer dissolved 
out into the water. After drying, the optical density of the photographic 
layer (colored in blue with phthalocyanine) remained in the hardened part 
was measured. Each of the image recording materials was variously tested 
with the heating time changed variously, and the heating time enough to 
attain a half (1/2) of the maximum density (or the optical density of the 
photographic layer before dipping in water) of the image density was 
checked for each case. (Said time was called t.sub.1/2.) The value of said 
t.sub.1/2 of each recording material is set forth in the Table 3. 
TABLE 3 
__________________________________________________________________________ 
Sample t.sub.1/2 
No. Hydrazine Derivative Reducing Agent (sec.) 
__________________________________________________________________________ 
1 .beta.-acetyl-p-aminophenylhydrazine (0.021 g) 
p-aminophenol (0.014 g) 
5 
2 " m-aminophenol (0.014 g) 
9 
3 " o-aminophenol (0.014 g) 
8 
4 " 2,6-dichloro-p-aminophenol (0.023 
7) 
5 " 3,5-dimethyl-p-aminophenol (0.018 
4) 
6 (comparative) 
" (none) 25 
7 .beta.-formyl-p-aminophenylhydrazine (0.010 g) 
p-aminophenol (0.014 g) 
9 
8 " m-aminophenol (0.014 g) 
15 
9 " o-aminophenol (0.014 g) 
10 
10 " 2,6-dichloro-p-aminophenol (0.023 
7) 
11 " 3,5-dimethyl-p-aminophenol (0.018 
6) 
12 (comparative) 
" (none) 18 
13 .beta.-formyl-p-methoxyphenylhydrazine (0.021 g) 
2,6-dichloro-p-aminophenol (0.023 
11 
14 (comparative) 
" (none) 45 
15 .beta.-acetyl-p-aminophenylhydrazine (0.021 g) 
p-anisidine (0.010 g) 
10 
16 " 2-methylresorcinol (0.016 
13 
17 " orcinol (0.016 g) 13 
18 " hydroquinone (0.014 g) 
12 
19 " p-methoxyphenol (0.016 g) 
14 
__________________________________________________________________________ 
From the above test samples, the following facts were noted. In the case 
that the photographic layer contained no hydrazine derivative, none of the 
reducing agents used could form any image at all, even after heating for 
200 seconds. Every combination of said reducing agent-hydrazine derivative 
reduced the t.sub.1/2 value to significantly as compared with the samples 
containing no reducing agent (see "comparative" sample in Table 3). The 
unexpected synergestic effect of the reducing agent and the hydrazine 
derivative was noted to be quite pronounced. 
Next, each of the recording materials was exposed through a step-wedge 
(optical density step: 0.3) and heated as in Example 15. The heating time 
was twice the time of said t.sub.1/2 value of each material as shown in 
Table 3. Afterwards, the non-hardened part was dissolved out in water in 
the same manner as mentioned above, and thus, a sharp blue image which was 
negative to the wedge and which comprised about six to eight-stage steps 
was formed in all recording materials (including the comparative cases). 
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.