Silver halide light-sensitive material comprising support, hardening layer and light-sensitive layer

A silver halide light-sensitive material comprises a support, a hardening layer and a light-sensitive layer in the order. An overcoating layer may be provided on the light-sensitive layer. The hardening layer contains an ethylenically unsaturated polymerizable compound or an ethylenically unsaturated cross-linkable polymer. The light-sensitive layer contains silver halide. The light-sensitive layer or the overcoating layer contains polyvinyl alcohol having a saponification degree of not less than 90%. The hardening layer or the light-sensitive layer contains a reducing agent. The hardening layer or the light-sensitive layer further contains a phenol compound represented by the formula (I): ##STR1## in which L.sup.1 is a divalent linking group; and each of the benzene rings A.sup.1 and B.sup.1 may have one to four substituent groups.

FIELD OF THE INVENTION 
The present invention relates to a silver halide light-sensitive material 
comprising a support, a hardening layer and a light-sensitive layer. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 4,629,676 (Hayakawa et al.) and European Patent No. 0174634 
(Fuji Photo Film Co., Ltd.) disclose an image forming method comprising 
the steps of imagewise exposing to light a light-sensitive material and 
heating the light-sensitive material. The light-sensitive material 
comprises a support and a light-sensitive hardening layer containing 
silver halide, a reducing agent and a polymerizable compound. The silver 
halide is developed by heating the light-sensitive material to form a 
polymer image. The polymerization is initiated by an oxidation radical of 
the reducing agent (including a radical formed from an oxidation product 
of the reducing agent). 
U.S. Pat. No. 5,122,443 (Takeda), 5,290,659 (Takeda) and European Patent 
No. 0426192 (Fuji Photo Film Co., Ltd.) disclose embodiments of the 
light-sensitive materials, which are advantageously used for the 
preparation of a lithographic plate. In the light-sensitive materials for 
the lithographic plate, the light-sensitive hardening layer preferably 
comprises a hardening layer and a light-sensitive layer. The hardening 
layer contains a polymerizable compound or a cross-linkable polymer. The 
light-sensitive layer contains silver halide. The hardening layer or the 
light-sensitive layer further contains a reducing agent. The 
light-sensitive material can further comprise an over-coating layer 
provided on the light-sensitive layer. 
A process for the preparation of a lithographic plate comprises the steps 
of imagewise exposing to light the light-sensitive material, heating the 
material, and removing the light-sensitive layer and the unhardened area 
of the hardening layer with an alkaline etching solution. The formed 
replica image is used as a printing plate. 
The hardening reaction of the polymerizable compound or the cross-linkable 
polymer at the heat development is inhibited by oxygen in the air. U.S. 
Pat. No. 5,122,443 (Takeda), 5,290,659 (Takeda) and European Patent No. 
0426192 (Fuji Photo Film Co., Ltd.) propose to use polyvinyl alcohol 
having a high saponification degree as a binder of the light-sensitive 
layer or the overcoating layer. The polyvinyl alcohol of the high 
saponification degree has a function of preventing oxygen from permeating 
into the hardening layer. The polyvinyl alcohol of the high saponification 
degree has another function of protecting components of the 
light-sensitive material (e.g., a reducing agent) from oxygen in the air 
while storing the material. 
SUMMARY OF THE INVENTION 
The applicant has studied the silver halide light-sensitive material to use 
the formed replica image as a printing plate. A silver halide 
light-sensitive material for practical use needs a latitude in a 
processing condition. The light-sensitive material is not always process 
at the optimum condition at a practical stage, which is different from an 
experimental stage. It is difficult to practically use a light-sensitive 
material that forms an image of low quality at a condition slightly 
different from the optimum condition, even though the material forms an 
image of high quality at the optimum condition at the experimental stage. 
The most important processing condition is the heating temperature at the 
heat development. 
An object of the present invention is to enlarge the latitude in a 
processing condition. 
Another object of the invention is to provide a silver halide 
light-sensitive material that forms a clear image (a sufficiently hardened 
replica image) even if the heating temperature is relatively low. 
The present invention provides a silver halide light-sensitive material 
comprising a support, a hardening layer, a light-sensitive layer and an 
overcoating layer in the order, said hardening layer containing an 
ethylenically unsaturated polymerizable compound or an ethylenically 
unsaturated cross-linkable polymer, said light-sensitive layer containing 
silver halide, said overcoating layer containing polyvinyl alcohol having 
a saponification degree of not less than 90%, and said hardening layer or 
said light-sensitive layer containing a reducing agent, wherein the 
hardening layer or the light-sensitive layer further contains a phenol 
compound represented by the formula (I): 
##STR2## 
in which L.sup.1 is a divalent linking group selected from the group 
consisting of --S--, --O--, --CO--, --SO--, --SO.sub.2 --, --NR.sup.1 --, 
a divalent aliphatic group, a divalent aromatic group, a divalent 
heterocyclic group and a combination thereof; R.sup.1 is hydrogen, an 
alkyl group or an aryl group; and each of the benzene rings A.sup.1 and 
B.sup.1 may have one to four substituent groups. 
The invention also provides a silver halide light-sensitive material 
comprising a support, a hardening layer and a light-sensitive layer in the 
order, said hardening layer containing an ethylenically unsaturated 
polymerizable compound or an ethylenically unsaturated cross-linkable 
polymer, said light-sensitive layer containing silver halide and polyvinyl 
alcohol having a saponification degree of not less than 90%, and said 
hardening layer or said light-sensitive layer containing a reducing agent, 
wherein the hardening layer or the light-sensitive layer further contains 
a phenol compound represented by the formula (I). 
The present invention is characterized in that the hardening layer or the 
light-sensitive layer further contains a phenol compound represented by 
the formula (I). The applicant has found that the phenol compound has a 
function of lowering a heating temperature for the heat development. 
Therefore, the silver halide light-sensitive material of the present 
invention can form a clear image (a sufficiently hardened replica image) 
even if the heating temperature is relatively low. The latitude of the 
heat development temperature is enlarged in the silver halide 
light-sensitive material of the present invention. Accordingly, the silver 
halide light-sensitive material is now suitable for practical use. The 
silver halide light-sensitive material has another advantage of saving the 
energy for the heat development. 
The phenol compound represented by the formula (I) has been known as an 
antioxidant of protecting a component of a light-sensitive material (e.g., 
a reducing agent) from oxygen in the air, as is described in Japanese 
Patent Provisional Publication No. 1(1989)-177029. Further, Japanese 
Patent Provisional Publication No. 4(1992)-116659 describes that the 
phenol compound is used at a heat development of a light-sensitive 
material containing silver halide, a reducing agent and a polymerizable 
compound. The phenol compound is used to protect a polymerization reaction 
of the polymerizable compound from oxygen in the air, which has a function 
of inhibiting the polymerization reaction. 
On the other hand, the silver halide light-sensitive material contains 
polyvinyl alcohol having a high saponification degree, which has a 
function of protecting the components of the light-sensitive material and 
the image forming reactions from oxygen in the air. In the examples of 
U.S. Pat. No. 5,122,443 (Takeda), the function of the polyvinyl alcohol 
having a high saponification degree was experimentally proved. Therefore, 
the silver halide light-sensitive material using the polyvinyl alcohol is 
free from the problems caused by oxygen in the air. 
The applicant has surprisingly found the new function of the phenol 
compound, namely the function of lowering the heat development 
temperature, which is effective in the silver halide light sensitive 
material that is free from the problems caused by oxygen in the air. The 
new function of the phenol compound and the new effect of the present 
invention are completely different from the known function of the phenol 
compound, that is the function of protecting the components of the 
light-sensitive material and the image forming reactions from oxygen in 
the air.

DETAILED DESCRIPTION OF THE INVENTION 
Phenol compound 
The phenol compound used in the present invention is represented by the 
formula (I): 
##STR3## 
In the formula (I), L.sup.1 is a divalent linking group selected from the 
group consisting of --S--, --O--, --CO--, --SO--, --SO.sub.2 --, 
--NR.sup.1 --, a divalent aliphatic group, a divalent aromatic group, a 
divalent heterocyclic group and a combination thereof. 
R.sup.1 is hydrogen, an alkyl group or an aryl group. R.sup.1 preferably is 
hydrogen or an alkyl group, and more preferably is hydrogen. The alkyl 
group preferably has a chain structure rather than a cyclic structure. The 
alkyl group of the chain structure may be branched. The alkyl group 
preferably has 1 to 6 carbon atoms, more preferably has 1 to 4 carbon 
atoms, further preferably has 1 to 3 carbon atoms, and most preferably has 
1 or 2 carbon atoms. The aryl group preferably has 6 to 30 carbon atoms, 
more preferably has 6 to 20 carbon atoms, further preferably has 6 to 15 
carbon atoms, and most preferably has 6 to 10 carbon atoms. 
The divalent aliphatic groups include an alkylene group, a substituted 
alkylene group, an alkenylene group, a substituted alkenylene group, an 
alkynylene group and a substituted alkynylene group. The alkylene group, 
the substituted alkylene group, the alkenylene group and the substituted 
alkenylene group are preferred, and the alkylene group and the substituted 
alkylene group are more preferred. 
The number of the total carbon atoms of the divalent aliphatic group 
(including a substituent group) is preferably in the range of 1 to 40, 
more preferably in the range of 1 to 20, further preferably in the range 
of 2 to 18, and most preferably in the range of 2 to 15. The number of the 
carbon atoms of the divalent aliphatic group (except for a substituent 
group) is preferably in the range of 1 to 20, more preferably in the range 
of 1 to 15, further preferably in the range of 1 to 10, and most 
preferably in the range of 1 to 6. 
The divalent aliphatic group preferably has a chain structure rather than a 
cyclic structure. The divalent aliphatic group of the chain structure may 
be branched. 
The divalent aromatic groups include an arylene group and a substituted 
arylene group. Examples of the arylene groups include phenylene and 
naphthylene. Phenylene is preferred, and 1,3-phenylene is particularly 
preferred. 
The number of the total carbon atoms of the divalent aromatic group 
(including a substituent group) is preferably in the range of 6 to 60, 
more preferably in the range of 6 to 40, further preferably in the range 
of 6 to 30, furthermore preferably in the range of 6 to 20, and most 
preferably in the range of 6 to 12. 
The divalent heterocyclic group preferably has a five-membered, 
six-membered or seven-membered ring, more preferably has a five-membered 
or six-membered ring, and most preferably has a six-membered ring. 
Examples of the hetero atoms include nitrogen, oxygen and sulfur. An 
aliphatic ring, an aromatic ring or another heterocyclic ring may be 
condensed with or combined by a spiro union to the ring of the divalent 
heterocyclic group. The divalent heterocyclic group may have a substituent 
group. 
The number of the total carbon atoms of the divalent heterocyclic group 
(including a substituent group) is preferably in the range of 1 to 50, 
more preferably in the range of 2 to 40, further preferably in the range 
of 2 to 30, furthermore preferably in the range of 3 to 20, and most 
preferably in the range of 3 to 12. 
Examples of the substituent groups of the divalent aliphatic, aromatic or 
heterocyclic groups include hydroxyl, a halogen atom (e.g., chloride), 
cyano, amino, a substituted amino group, a heterocyclic group, an acyl 
group and an acyloxy group. The substituent group of the substituted amino 
group is an aliphatic group or an aromatic group. The acyl group is 
defined as --CO--R (wherein R is an aliphatic group, an aromatic group or 
a heterocyclic group). The acyloxy group is defined as --O--CO--R (wherein 
R is an aliphatic group, an aromatic group or a heterocyclic group). 
Examples of the substituent groups of the divalent aromatic or 
heterocyclic groups further include an aliphatic group. The definitions 
and examples of the aliphatic, aromatic and heterocyclic groups are the 
same as those of the substituent groups of the benzene rings A.sup.1 and 
B.sup.1. 
Examples of the divalent linking groups of the combinations are shown 
below. 
L11: --S--S-- 
L12: --AL--S--AL-- 
L13: --AL--O--AL-- 
L14: --AL--AR--AL-- 
L15: --AL--CO--O--AL--O--CO--AL- 
L16: --AL--CO--O--AL--Hc--AL--O--CO--AL-- 
L17: --AL--O--CO--AL--Hc--AL--CO--O--AL-- 
L18: --AL--CO--O--AL--S--AL--O--CO--AL-- 
L19: --AL--CO--NR.sup.11 --AL--NR.sup.12 --CO--AL-- 
in which AL is a divalent aliphatic group; AR is a divalent aromatic group; 
Hc is a divalent heterocyclic group; and each of R.sup.11 and R.sup.12 
independently has the same meanings as those of R.sup.1. 
In the formula (I), each of the benzene rings A.sup.1 and B.sup.1 may have 
one to four substituent groups. 
Examples of the substituent groups include hydroxyl, a halogen atom (e.g., 
chloride), cyano, amino, a substituted amino group, an aliphatic group, an 
aromatic group, a heterocyclic group, an acyl group and an acyloxy group. 
The substituent group of the substituted amino group is an aliphatic group 
or an aromatic group. The acyl group is defined as --CO--R (wherein R is 
an aliphatic group, an aromatic group or a heterocyclic group). The 
acyloxy group is defined as --O--CO--R (wherein R is an aliphatic group, 
an aromatic group or a heterocyclic group). 
The aliphatic groups include an alkyl group, a substituted alkyl group, an 
alkenyl group, a substituted alkenyl group, an alkynyl group, a 
substituted alkynyl group, an aralkyl group and a substituted aralkyl 
group. The alkyl group, the substituted alkyl group, the alkenyl group, 
the substituted alkenyl group, the aralkyl group and the substituted 
aralkyl group are preferred, the alkyl group, the substituted alkyl group, 
the alkenyl group and the substituted alkenyl group are more preferred, 
the alkyl group and the substituted alkyl group are further preferred, and 
the alkyl group is most preferred. 
The number of the total carbon atoms of the aliphatic group (including a 
substituent group) is preferably in the range of 1 to 40, more preferably 
in the range of 1 to 20, further preferably in the range of 1 to 15, and 
most preferably in the range of 1 to 10. The number of the carbon atoms of 
the aliphatic group (except for a substituent group) is preferably in the 
range of 1 to 20, more preferably in the range of 1 to 15, further 
preferably in the range of 1 to 10, and most preferably in the range of 1 
to 6. 
The aliphatic group preferably has a chain structure rather than a cyclic 
structure. The aliphatic group of the chain structure may be branched. 
The aromatic groups include an aryl group and a substituted aryl group. 
Examples of the aryl groups include phenyl and naphthyl. 
The number of the total carbon atoms of the aromatic group (including a 
substituent group) is preferably in the range of 6 to 60, more preferably 
in the range of 6 to 40, further preferably in the range of 6 to 30, 
furthermore preferably in the range of 6 to 20, and most preferably in the 
range of 6 to 12. 
The heterocyclic group preferably has a five-membered, six-membered or 
seven-membered ring, more preferably has a five-membered or six-membered 
ring, and most preferably has a six-membered ring. Examples of the hetero 
atoms include nitrogen, oxygen and sulfur. An aliphatic ring, an aromatic 
ring or another heterocyclic ring may be condensed with or combined by a 
Spiro union to the ring of the heterocyclic group. The heterocyclic group 
may have a substituent group. 
The number of the total carbon atoms of the heterocyclic group (including a 
substituent group) is preferably in the range of 1 to 50, more preferably 
in the range of 2 to 40, further preferably in the range of 2 to 30, 
furthermore preferably in the range of 3 to 20, and most preferably in the 
range of 3 to 12. 
Examples of the substituent groups of the aliphatic, aromatic or 
heterocyclic groups include hydroxyl, a halogen atom (e.g., chloride), 
cyano, amino, a substituted amino group, a heterocyclic group, an acyl 
group and an acyloxy group. The substituent group of the substituted amino 
group is an aliphatic group or an aromatic group. The acyl group is 
defined as --CO--R (wherein R is an aliphatic group, an aromatic group or 
a heterocyclic group). The acyloxy group is defined as --O--CO--R (wherein 
R is an aliphatic group, an aromatic group or a heterocyclic group). 
Examples of the substituent groups of the aromatic or heterocyclic groups 
further include an aliphatic group. 
The phenol compound preferably is a hindered phenol compound represented by 
the formula (II). The hindered phenol compound means a phenol compound 
having a bulk substituent group at its ortho position such as a tertiary 
alkyl group, which causes a steric hindrance. 
##STR4## 
In the formula (II), L.sup.2 is a divalent linking group selected from the 
group consisting of --S--, --O--, --CO--, --SO--, --SO.sub.2 --, 
--NR.sub.2 --, a divalent aliphatic group, a divalent aromatic group, a 
divalent heterocyclic group and a combination thereof. 
R.sup.2 is hydrogen, an alkyl group or an aryl group. R.sup.2 preferably is 
hydrogen or an alkyl group, and more preferably is hydrogen. The alkyl 
group preferably has a chain structure rather than a cyclic structure. The 
alkyl group of the chain structure may be branched. The alkyl group 
preferably has 1 to 6 carbon atoms, more preferably has 1 to 4 carbon 
atoms, further preferably has 1 to 3 carbon atoms, and most preferably has 
1 or 2 carbon atoms. The aryl group preferably has 6 to 30 carbon atoms, 
more preferably has 6 to 20 carbon atoms, further preferably has 6 to 15 
carbon atoms, and most preferably has 6 to 10 carbon atoms. 
The definitions and examples of the divalent linking groups are the same as 
those of L.sup.1 in the formula (I). 
In the formula (II), each of R.sup.21, R.sup.22, R.sup.23, R.sup.24, 
R.sup.25 and R.sup.26 independently is an alkyl group having 1 to 6 carbon 
atoms. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 
has 1 to 3 carbon atoms, further preferably has 1 or 2 carbon atoms 
(methyl or ethyl), and most preferably has 1 carbon atom (methyl). 
In the formula (II), each of the benzene rings A.sup.2 and B.sup.2 may have 
one to three substituent groups. Examples of the substituent groups are 
the same as those of the substituent groups of the benzene rings Al and 
B.sup.1 in the formula (I). 
Examples of the phenol compounds represented by the formula (I) are shown 
below. 
##STR5## 
The phenol compound represented by the formula (I) is added to the 
hardening layer or the light-sensitive layer, and is preferably added to 
the hardening layer. The phenol compound is dissolved or dispersed in a 
coating solution of the hardening layer or the light-sensitive layer. 
Whether the phenol compound is dissolved or dispersed depends on a solvent 
of the coating solution. Further, a solution of the phenol compound in a 
solvent other than the solvent of the coating solution can be emulsified 
in the coating solution. 
The amount of the phenol compound is preferably in the range of 0.05 to 20 
mol, and more preferably in the range of 0.1 to 1 mol based on 1 mol of 
the reducing agent. 
Layered structure 
The silver halide light-sensitive material comprises a support, a hardening 
layer and a light-sensitive layer in the order. The light-sensitive 
material can comprise three or more layers such as a hardening layer, a 
light-sensitive layer and an overcoating layer (or an image formation 
accelerating layer). An adhesive layer may be provided between the 
hardening layer and the light-sensitive layer. A reducing agent is added 
to the hardening layer or the light-sensitive layer, and is preferably 
added to the light-sensitive layer. Polyvinyl alcohol having a 
saponification degree of not less than 90% is added to the uppermost layer 
(an overcoating layer in the case that the overcoating layer is provided 
or a light-sensitive layer in the case that the light-sensitive layer is 
not provided). 
The components of the above-mentioned layers are preferably uniformly 
dispersed in the layers without use of microcapsules. 
The light-sensitive material may further have other optional layers such as 
an adhesive layer, a strippable layer, an undercoating layer and an 
intermediate layer. 
Preferred layered structures are described below referring to the drawings. 
FIG. 1 is a sectional view schematically illustrating a preferred 
embodiment of a silver halide light-sensitive material. 
The light-sensitive material shown in FIG. 1 comprises an aluminum support 
(1), a hardening layer (2), a light-sensitive layer (3) and an overcoating 
layer (4) in that order. The hardening layer (2) contains a phenol 
compound (21), an ethylenically unsaturated polymerizable compound (22) 
and an ethylenically unsaturated cross-linkable polymer (23). The 
light-sensitive layer (3) contains silver halide (31), a reducing agent 
(32) and a hydrophilic polymer (33). The overcoating layer contains a base 
precursor (41) and polyvinyl alcohol having a saponification degree of not 
less than 90% (42). 
FIG. 2 is a sectional view schematically illustrating another preferred 
embodiment of a silver halide light-sensitive material. 
The light-sensitive material shown in FIG. 2 comprises an aluminum support 
(1), a hardening layer (2) and a light-sensitive layer (3) in the order. 
The hardening layer (2) contains a phenol compound (21), an ethylenically 
unsaturated polymerizable compound (22) and an ethylenically unsaturated 
cross-linkable polymer (23). The light-sensitive layer (3) contains silver 
halide (31), a reducing agent (32), a base precursor (33) and polyvinyl 
alcohol having a saponification degree of not less than 90% (34). 
Support 
The support can be made of a paper, a synthetic paper, a paper laminated 
with a synthetic resin (e.g., polyethylene, polypropylene, polystyrene), a 
plastic (e.g., polyethylene terephthalate, polycarbonate, polyimide, 
Nylon, cellulose triacetate) film, a metal (e.g., aluminum, aluminum 
alloy, zinc, iron, copper) plate or a paper or plastic film laminated with 
the metal. Further, the metal can be evaporated onto the paper or plastic 
film to form the support. 
In the case that the light-sensitive material is used for the preparation 
of a lithographic plate, the support is preferably made of an aluminum 
plate, a polyethylene terephthalate film, a polycarbonate film, a paper or 
a synthetic paper. A complex sheet can also be used as the support. For 
example, an aluminum sheet can be laminated on the polyethylene 
terephthalate film. 
An aluminum support is particularly preferred. The aluminum support 
preferably has a thickness in the range of 0.1 to 0.5 mm. 
The aluminum support is preferably treated to form a rough surface 
(graining treatment) or a hydrophilic surface. 
The treatment for the rough surface can be conducted by an electrochemical 
graining treatment and/or a mechanical graining treatment. According to 
the electrochemical graining treatment, a current passes through an 
aluminum plate in an electrolytic solution of hydrochloric acid or nitric 
acid. The mechanical graining treatment includes a wire brushing method, a 
ball graining method and a brash graining method. In the wire brushing 
method, the surface of aluminum plate is scratched with a metal wire. In 
the ball graining method, the surface of aluminum plate is grained with 
graining balls and a graining agent. In the brash graining method, the 
surface is grained with a Nylon brash and a graining agent. 
The grained aluminum plate is then chemically etched with an alkali or an 
acid. An alkali etching method is industrially advantageous. Examples of 
the alkali agents include sodium carbonate, sodium aluminate, sodium 
metasilicate, sodium phosphate, sodium hydroxide, potassium hydroxide and 
lithium hydroxide. The alkali solution preferably has a concentration in 
the range of 1 to 50 wt.%. The temperature of the alkali treatment is 
preferably in the range of 20 to 100.degree. C. The treatment conditions 
are preferably so adjusted that the amount of the dissolved aluminum is in 
the range of 5 to 20 g per m.sup.2. 
The aluminum plate is usually washed with an acid to remove smut from the 
surface after the alkali etching treatment. Examples of the acids include 
nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric 
acid and borofluoric acid. 
The smut removing treatment can also be conducted according to a 
conventional method after the electrochemical graining treatment. For 
example, an aluminum plate can be treated with 15 to 65 wt. % sulfuric 
acid at a temperature in the range of 50 to 90.degree. C. 
The surface treated aluminum plate can be subjected to an anodizing 
treatment or a chemical treatment. The anodizing treatment can be 
conducted according to a conventional method. In more detail, a direct or 
alternative current passes through an aluminum plate in a solution of an 
acid to form an anodic oxide layer on the surface of the plate. Examples 
of the acids include sulfuric acid, phosphoric acid, chromic acid, oxalic 
acid, sulfamic acid and benzenesulfonic acid. The conditions of the 
anodizing treatment depend on the contents of the electrolytic solution. 
The concentration of the electrolytic solution is preferably in the range 
of 1 to 80 wt. %, the temperature of the solution is preferably in the 
range of 5 to 70.degree. C., the current density is preferably in the 
range of 0.5 to 60 A/dm2, the voltage is preferably in the range of 1 to 
100 v, and the time for the electrolysis is preferably in the range of 10 
to 100 seconds. 
The anodizing treatment is preferably conducted in sulfuric acid at a high 
current density. Phosphoric acid is also preferably used for the anodizing 
treatment. 
After the anodizing treatment, the aluminum plate can be treated with an 
alkali metal silicate. For example, the aluminum plate can be immersed in 
an aqueous solution of sodium silicate. An undercoating layer can be 
provided on the aluminum support to improve the adhesion between the 
support and the hardening layer or to improve a printing character. 
Undercoating layer 
An undercoating layer (hydrophilic layer) can be provided on not only the 
above-mentioned aluminum support, but also a support having a hydrophobic 
(or not sufficiently hydrophilic) surface (e.g., a polymer film). 
Examples of the components of the undercoating layer include a polymer 
(e.g., gelatin, casein, polyvinyl alcohol, ethyl cellulose, phenol resin, 
styrene-maleic anhydride resin, polyacrylic acid), an amine (e.g., 
monoethanol amine, diethanol amine, triethanol amine, tripropanol amine) 
and a salt thereof (e.g., chloride, oxalate, phosphate), an 
monoaminomonocarboxylic acid (e.g., aminoacetic acid, alanine), an 
oxyamino acid (e.g., serine, threonine, dihydroxyethylglycine), a sulfur 
containing amino acid (e.g., cysteine, cystine), a monoaminodicarboxylic 
acid (e.g., aspartic acid, glutamic acid), an aromatic amino acid (e.g., 
p-hydroxylphenylglycine, phenylalanine, anthranilic acid), an aliphatic 
aminosulfonic acid (e.g., sulfamic acid, cyclohexylsulfamic acid) and a 
(poly)aminopolyacetic acid (e.g., ethylenediaminetetraacetic acid, 
nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, 
hydroxyethylethylenediamineacetic acid, ethylenediaminediacetic acid, 
cycloethylenediaminetetraacetic acid, diethylenetriaminepentaaceitic acid, 
glycoletherdiaminetetraacetic acid). All or a part of the acidic groups of 
the above-mentioned compound may form a salt (e.g., sodium salt, potassium 
salt, ammonium salt). Two or more components can be used in combination. 
In the case that a polymer film is used as a support, hydrophilic fine 
particles (e.g., silica particles) are preferably added to a hydrophilic 
undercoating layer in place of the graining treatment of an aluminum 
support. 
Hardening layer 
The hardening layer contains an ethylenically unsaturated polymerizable 
compound or an ethylenically unsaturated cross-linkable polymer. The 
hardening layer preferably contains the polymerizable compound and the 
cross-linkable polymer. 
The amount of the cross-linkable polymer is preferably in the range of 30 
to 95 wt. %, and more preferably in the range of 50 to 90 wt. % based on 
the amount of the hardening layer. 
The amount of the ethylenically unsaturated polymerizable compound is 
preferably in the range of 3 to 200 wt. %, and more preferably in the 
range of 10 to 100 wt. % based on the amount of the cross-linkable 
polymer. 
The hardening layer preferably has a thickness in the range of 0.1 to 20 
.mu.m, and more preferably in the range of 0.3 to 7 .mu.m. 
Adhesive layer 
The adhesive layer contains a polymer having a function of improving the 
adhesion between the hardening layer and the light-sensitive layer. 
The coating amount of the adhesive layer is preferably in the range of 0.01 
to 2 g per m.sup.2, more preferably in the range of 0.02 to 1.5 g per 
m.sup.2, and most preferably in the range of 0.025 to 1.0 g per m.sup.2. 
Light-sensitive layer 
The light-sensitive layer contains silver halide, and preferably further 
contains a hydrophilic polymer. 
The coating amount of silver halide is preferably in the range of 0.01 to 5 
g per m.sup.2, more preferably in the range of 0.03 to 1 g per m.sup.2, 
and most preferably in the range of 0.05 to 0.3 g per m.sup.2. 
The light-sensitive layer preferably has a thickness in the range of 0.07 
to 13 .mu.m, and more preferably in the range of 0.2 to 5 .mu.m. 
Overcoating layer 
An overcoating layer has a function of preventing oxygen in the air from 
permeating into the hardening layer. Oxygen functions as a polymerization 
inhibitor. The overcoating layer can function as a protective layer. The 
overcoating layer can also function as an image formation accelerating 
layer, where the layer further contains a component (e.g., a base, a base 
precursor, a reducing agent, a heat development accelerator) that 
accelerates an image forming reaction. 
The overcoating layer preferably has a thickness in the range of 0.3 to 20 
.mu.m, more preferably in the range of 0.5 to 7 .mu.m. 
Intermediate layer 
An intermediate layer can be provided between the layers. 
The intermediate layer can function as an antihalation layer. a filter 
layer or a barrier layer. The antihalation layer and the filter layer is a 
functional layer containing a dye. The barrier layer prevents components 
from moving between layers when the light-sensitive material is stored. 
The composition of the intermediate layer is determined according to its 
function. 
The intermediate layer preferably has a thickness of not more than 10 
.mu.m. 
Silver halide 
Silver halide is silver chloride, silver bromide, silver iodide, silver 
chlorobromide, silver chloroiodide, silver iodobromide or silver 
chloroiodobromide in the form of grains. 
The crystal forms of silver halide grains preferably are cubic or 
tetradecahedron. Irregular forms and mixed forms as well as the above 
mentioned regular forms can be used in the silver halide emulsions. 
Examples of the irregular forms include a potato-like form, a spherical 
form and a tabular form. The tabular form usually has an aspect ratio 
(diameter per thickness) of 5 or more. 
The silver halide grains may be extremely small grains having a grain 
diameter (diameter of projected area) of less than 0.01 .mu.m. The grains 
may also be relatively large grains having a diameter of more 10 .mu.m. A 
monodispersed emulsion is preferred to a polydispersed emulsion. The 
monodispersed emulsion is described in U.S. Pat. Nos. 3,574,628, 3,655,394 
and British Patent No. 1,413,748. 
With respect to the crystal structure of the silver halide grains, the 
individual grains have a homogeneous halogen composition or a 
heterogeneous halogen composition. In the heterogeneous composition, the 
composition varies from the outer surface portion to the inside portion. 
The grains may have a multi-layered structure. Further, the silver halide 
grains may be conjugated with other silver halide grains having different 
halogen composition through epitaxial conjugation. The grains may be 
conjugated with compounds other than the silver halide such as silver 
rhodanate and lead oxide. 
Various substances in the form of salt can be added to the silver halide 
grains. Examples of the substances include copper, thallium, lead, 
cadmium, zinc, chalcogens (e.g., sulfur, selenium, tellurium), gold, and 
noble metals of group VIII (e.g., rhodium, iridium, iron, platinum, 
palladium). The salts are added to the emulsion at the grain formation or 
after the grain formation according to a conventional process. The 
conventional process is described in U.S. Pat. Nos. 1,195,432, 1,191,933, 
2,448,060, 2,628,167, 2,950,972, 3,488,709, 3,737,313, 3,772,031, 
4,269,927 and Research Disclosure (RD), No. 13,452 (June 1975). 
The silver halide grains can be doped with iridium ion by adding an aqueous 
solution of an iridium compound to a silver halide emulsion. Examples of 
water-soluble iridium compounds include hexachloroiridic(III) salts and 
hexachloroiridic(IV) salts. The silver halide grains can also be doped 
with rhodium ion by adding an aqueous solution of a rhodium compound to a 
silver halide emulsion. Examples of water-soluble rhodium compounds 
include rhodium ammonium chloride, rhodium trichloride and rhodium 
chloride. 
The iridium compound or the rhodium compound can be dissolved in a halide 
solution for forming silver halide grains. The aqueous solution of the 
iridium compound or the rhodium compound can be used before or after the 
grain formation. Further, the solution can be added to the emulsion 
between the grain formation and a chemical sensitization. The solution is 
preferably added at the stage of the grain formation. The iridium or 
rhodium ion is preferably used in an amount of 10.sup.-8 to 10.sup.-3 mol, 
and more preferably in an amount of 10.sup.-7 to 10.sup.-5 mol based on 1 
mol of silver halide. 
Two or more kinds of silver halide grains that differ in halogen 
composition, crystal habit, grain size, or other features from each other 
can be used in combination. 
The silver halide is preferably used in the form of an emulsion. The silver 
halide emulsion can be prepared by known processes, which are described in 
Research Disclosure (RD), No. 17,643, pages 22 to 23 (December 1978), 
(Emulsion preparation and types); and Research Disclosure, No. 18,716, 
page 648, (November 1979). 
The silver halide emulsion is generally used after a physical ripening and 
a chemical sensitization. The silver halide grains preferably have a low 
fogging value. 
Various additives can be used in the ripening or sensitizing steps. The 
additives are described in Research Disclosure, No. 17,643 and No. 18,716. 
The chemical sensitizer is described in No. 17,643 (page 23) and No. 
18,716 (page 648, right column). Other additives are also described in 
Research Disclosure. For example, a sensitivity-increasing agent is 
described in No. 18,716 (page 648, right column). An anti-fogging agent 
and a stabilizer are described in No. 17,643 (pages 24 to 25) and No. 
18,716 (page 649, right column), respectively. 
The silver halide emulsion is usually subjected to a spectral 
sensitization. Various spectral sensitizing dyes are known in a 
conventional silver halide photography. Examples of the sensitizing dyes 
include cyanine dyes, merocyanine dyes, complex merocyanine dyes, 
holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. 
The spectral sensitizing dyes can be used to adjust the spectral 
sensitivity of the light-sensitive material to wavelength of two or more 
light sources such as various laser beams (e.g., semiconductor laser, 
helium neon laser, argon ion laser, helium cadmium laser, YAG laser) and a 
light emission diode. For example, two or more sensitizing dyes are used 
for silver halide grains in a light-sensitive layer so that a 
light-sensitive material can be exposed to two or more light sources. 
A supersensitizer can be added to the emulsion in addition to the 
sensitizing dye. The supersensitizer itself has neither a spectral 
sensitization effect nor an absorption of visible light, but shows a 
supersensitizing effect on the sensitizing dye. 
The spectral sensitizing dyes are described in Research Disclosure No. 
17643 (December 1978), pages 23 to 24. The supersensitizers are described 
in Research Disclosure No. 18716 (November 1979), page 649. 
Organic metallic salt 
An organic metallic salt can be added to the light-sensitive layer 
containing silver halide. An organic silver salt is particularly 
preferred. 
Examples of organic moieties of the salts include triazoles, tetrazoles, 
imidazoles, indazoles, thiazoles, thiadiazoles, azaindenes. An aliphatic, 
aromatic or heterocyclic compound having a mercapto group can also be used 
as the organic moiety. Further, silver carboxylates and acetylene silver 
can be used as the organic silver salt. Two or more organic metallic salts 
can be used in combination. 
The organic silver salt is generally used in an amount of 10.sup.-5 to 10 
mol, and preferably 10.sup.-4 to 1 mol based on 1 mol of silver halide. 
Reducing agent 
The reducing agent has a function of reducing the silver halide or a 
function of accelerating a hardening reaction of a polymerizable compound 
or a cross-linkable polymer. 
Examples of the reducing agents include hydrazines (including hydrazides), 
hydroquinones, catechols, p-aminophenols, p-phenylenediamines, 
3-pyrazolidones, 3-aminopyrazoles, 4-amino-5-pyrazolones, 5-aminouracils, 
4,5-dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- or 
p-sulfonamidophenols, o- or p-sulfonamidonaphthols, 
2,4-disulfonamidephenols, 2,4-disulfonamidenaphthols, o- or 
p-acylaminophenols, 2-sulfonamidoindanones, 4-sulfonamido-5-pyrazolones, 
3-sulfonamidoindoles, sulfonamidopyrazolobenzimidazoles, 
sulfonamidopyrazolotriazoles and .alpha.-sulfonamidoketones. Hydrazines 
(including hydrazides) are preferred, and hydrazides are more preferred. 
The hydrazide compound is represented by the formula (III): 
##STR6## 
In the formula (III), R.sup.31 is hydrogen, an alkyl group or an aryl 
group. R.sup.31 preferably is an alkyl group or an aryl group, and more 
preferably is an aryl group. The alkyl group preferably has a chain 
structure rather than a cyclic structure. The alkyl group of the chain 
structure may be branched. The alkyl group preferably has 1 to 6 carbon 
atoms, more preferably has 1 to 4 carbon atoms, further preferably has 1 
to 3 carbon atoms, and most preferably has 1 or 2 carbon atoms. The aryl 
group preferably has 6 to 30 carbon atoms, more preferably has 6 to 20 
carbon atoms, further preferably has 6 to 15 carbon atoms, and most 
preferably has 6 to 10 carbon atoms. The alkyl group and the aryl group 
may have a substituent group. Examples of the substituent groups include 
hydroxyl, a halogen atom (e.g., chloride), cyano, amino, a substituted 
amino group, a heterocyclic group, an acyl group and an acyloxy group. An 
aryl group substituted with chloride is particularly preferred. 
In the formula (III), the benzene ring C may have one to five substituent 
groups. Examples of the substituent groups include hydroxyl, a halogen 
atom (e.g., chloride), cyano, amino, a substituted amino group, a 
heterocyclic group, an acyl group and an acyloxy group. The benzene ring C 
is preferably substituted with chloride. 
The reducing agents (including compounds referred to as developing agent or 
hydrazine derivative) are described in Japanese Patent Provisional 
Publication Nos. 61(1986)-183640, 61(1986)-183535, 61(1986)-228441, 
62(1987)-70836, 61(1987)-86354, 62(1987)-86355, 62(1987)-206540, 
62(1987)-264041, 62(1987)-109437, 63(1988)-254442, 1(1989)-267536, 
2(1990)-141756, 2(1990)-141757, 2(1990)-207254, 2(1990)-262662 and 
2(1990)-269352. The reducing agents are also described in T. James, The 
Theory of the Photographic Process, 4th edition, pages 291 to 334 (1977), 
Research Disclosure, Vol. 170, No. 17029, pages 9 to 15 (June 1978), and 
Research Disclosure, Vol. 176, No. 17643, pages 22 to 31 (December 1978). 
Further, a reducing agent precursor can be used as the reducing agent. The 
precursor (described in Japanese Patent Provisional Publication No. 
62(1987)-210446) can release a reducing agent under heating or in contact 
with a base. 
When the reducing agent is basic, that is, it forms a salt with an acid, 
the reducing agent can be used in the form of a salt with an acid. The 
reducing agents can be used singly or in combination. Certain interactions 
between those reducing agents may be expected where two or more reducing 
agents are used in combination. One of the interactions is for an 
acceleration of reduction of silver halide (or an organic silver salt) 
through so-called super-additivity. The other interaction is for a chain 
reaction between an oxidant of one reducing agent formed by a reduction of 
silver halide (or an organic silver salt) oxidation-reduction reaction and 
another reducing agent. The chain reaction induces the polymerization of 
the polymerizable compound. 
The reducing agent is used in an amount of 0.1 to 10 mol, and more 
preferably 0.25 to 2.5 mol based on 1 mol of silver halide. 
Antifogging agent, silver development accelerator, stabilizer 
The light-sensitive material can contain an antifogging agent, a silver 
development accelerator or a stabilizer. Examples of these compounds 
include mercapto compounds (described in Japanese Patent Provisional 
Publication No. 59(1984)-111636), azoles or azaindenes (described in 
Research Disclosure No. 17643 (1978), pages 24 to 25), nitrogen-containing 
carboxylic acids or the phosphoric acids (described in Japanese Patent 
Provisional Publication No. 59(1984)-168442), acetylene compounds 
(described in Japanese Patent Provisional Publication No. 62(1987)-87957) 
and sulfonamides (described in Japanese Patent Provisional Publication No. 
61(1987)-178232). 
An aromatic (a carbon or heterocyclic ring) mercapto compound can also be 
used as an antifogging agent or a silver development accelerator. An 
aromatic heterocyclic mercapto compound, particularly a mercapto triazole 
derivative is preferred. The mercapto compound can be used in the form of 
a mercapto silver (silver salt). 
These compounds are generally used in an amount of 10.sup.7 to 1 mol based 
on 1 mol of the silver halide. 
Hydrophilic polymer 
A hydrophilic polymer is used as a binder of a hydrophilic layer, such as a 
light-sensitive layer, an overcoating layer and an intermediate layer. 
The hydrophilic polymer has a hydrophilic group or a hydrophilic bond in 
its molecule. Examples of the hydrophilic group include carboxyl, hydroxyl 
(including alcohol and phenol), sulfo, sulfonamido, sulfonimido and amido. 
Examples of the hydrophilic bond include urethane bond, ether bond and 
amido bond. 
Natural or synthetic polymers can be used as the hydrophilic polymer. The 
hydrophilic polymers are described in Japanese Patent Provisional 
Publication No. 5(1993)-249667. 
Polyvinyl alcohol is a particularly preferred hydrophilic polymer. 
Polyvinyl alcohol used in the uppermost layer has a high saponification 
degree of not lower than 90%, preferably of not lower than 93 %, more 
preferably of not lower than 95%, further preferably of not lower than 
97%, and most preferably of not lower than 98%. The polyvinyl alcohol 
having the high saponification degree has a very low transmission 
coefficient of oxygen. 
Polyvinyl alcohol may be denatured by copolymerization with another 
monomer. A copolymer of vinyl acetate and another monomer is saponified to 
form the denatured polyvinyl alcohol. Examples of the monomer 
copolymerized with the vinyl acetate include ethylene, vinyl higher 
carboxylate, a higher alkyl vinyl ether, methyl methacrylate and 
acrylamide. 
Polyvinyl alcohol may also be denatured after the saponification. Hydroxyl 
in polyvinyl alcohol can be modified by etheration, esterification or 
acetylation. 
A cross-linked polyvinyl alcohol can also be used. Examples of the 
cross-linking agents include aldehydes, methylol compounds, epoxy 
compounds, diisocyanates, divinyl compounds, dicarboxylic acids and 
inorganic cross-linking agents (e.g., boric acids). 
The molecular weight of the hydrophilic polymer is preferably in the range 
of 3,000 to 500,000. 
Ethylenically unsaturated polymerizable compound 
The polymerizable compound used in the present invention has an 
ethylenically unsaturated group. 
Examples of the ethylenically unsaturated polymerizable compounds include 
acrylic acids, salts thereof, acrylic esters, acrylamides, methacrylic 
acids, salts thereof, methacrylic esters, methacrylamides, maleic 
anhydride, maleic esters, itaconic esters, styrenes, vinyl ethers, vinyl 
esters, N-vinyl heterocyclic compounds, allyl ethers, allyl esters, and 
derivatives thereof. 
Acrylic esters and methacrylic esters are preferred. Examples of the 
(meth)acrylic esters include pentaerythritol tetra(meth)acrylate, 
trimethylolpropane tri(meth)acrylate, dipentaerythritol 
hexa(meth)acrylate, polyester (meth)acrylate and polyurethane 
(meth)acrylate. 
Two or more ethylenically unsaturated polymerizable compounds can be used 
in combination. 
Hydrophobic polymer 
A hydrophilic polymer preferably has a cross-linkable functional group. The 
cross-linkable functional group can be introduced into the main chain or 
side chain of the polymer molecule. The cross-linkable functional group 
can also be introduced into the polymer by copolymerization. 
Examples of the polymer having an ethylenically unsaturated bond in its 
main chain include poly-1,4-butadiene, poly-1,4-isoprene and natural or 
synthetic rubbers. Examples of the polymer having an ethylenically 
unsaturated bond in its side chain include polymers of acrylic or 
methacrylic ester or amide having a specific residue, which means R of 
--COOR (ester) or --CONHR (amide). Examples of the specific residues 
include --(CH.sub.2).sub.n --CR.sup.1 .dbd.CR.sup.2 R.sup.3, --(CH.sub.2 
O).sub.n --CH.sub.2 CR.sup.1 .dbd.CR.sub.2 R.sup.3, --(CH.sub.2 CH.sub.2 
O).sub.n --CH.sub.2 CR.dbd.CR.sub.2 R.sup.3, --(CH.sub.2).sub.n 
--NH--CO--O--CH.sub.2 CR.sup.1 .dbd.CR.sup.2 R.sup.3, --(CH.sub.2).sub.n 
--O--CO--CR.sup.1 .dbd.CR.sup.2 R.sup.3 and --(CH.sub.2 CH.sub.2 O).sub.n 
--X. In the formulas, each of R.sup.1, R.sup.2 and R.sup.3 independently 
is hydrogen, a halogen atom, an alkyl group, an aryl group, an alkoxy 
group and aryloxy group. The number of the carbon atoms contained in 
R.sup.1, R.sup.2 or R.sup.3 is not more than 20. R.sup.1 and R.sup.2 or 
R.sup.3 may be combined to form a ring. In the formulas, n is an integer 
of 1 to 10. X is dicyclopentadienyl. 
Examples of the ester residues include --CH.sub.2 CH.dbd.CH.sub.2 
(described in Japanese Patent Publication No. 7(1995)-21633), --CH.sub.2 
CH.sub.2 O--CH.sub.2 CH.dbd.CH.sub.2, --CH.sub.2 C(CH.sub.3).dbd.CH.sub.2, 
--CH.sub.2 CH.dbd.CH--C.sub.6 H.sub.5, --CH.sub.2 CH.sub.2 
OCOCH.dbd.CH--C.sub.6 H.sub.5, --CH.sub.2 CH.sub.2 --NHCOO--CH.sub.2 
CH.dbd.CH.sub.2 and --CH.sub.2 CH.sub.2 O--X (wherein X is 
dicyclopentadienyl). Examples of the amide residues include --CH.sub.2 
CH.dbd.CH.sub.2, --CH.sub.2 CH.sub.2 --1--Y (wherein Y is cyclohexene) and 
--CH.sub.2 CH.sub.2 --OCO--CH.dbd.CH.sub.2. 
The cross-linkable polymer is hardened by adding a free radical to the 
unsaturated bond (or group). The free radical functions as a 
polymerization initiator or a chain extender. The polymers are 
cross-linked with each other directly or by a chain reaction of a 
polymerizable compound. The polymer can also be cross-linked by a reaction 
of polymer radicals, which are formed by detaching an atom of the polymers 
(e.g., hydrogen attached to carbon adjacent to the unsaturated bond) by a 
free radical. 
Examples of non-cross-linkable (or weak cross-linkable) hydrophobic 
polymers include polyacrylic esters, polymethacrylic esters (e.g., 
polymethyl methacrylate, polybenzyl methacrylate), polyacrylamides and 
polymethacrylamides. These polymers have a saturated aliphatic residue or 
an aromatic residue in place of the above-mentioned ethylenically 
unsaturated residue (R). 
Other examples of non-cross-linkable polymers include polyacrylic esters, 
polymethacrylic esters, polyvinyl acetate, polyvinyl chloride, 
polyvinylidene chloride, polyacrylonitrile, polymethacrylonitrile, 
polyethylene, polyvinyl pyridine, polyvinyl imidazole, polyvinyl butyral, 
polyvinyl formal, polyvinyl pyrrolidone, chlorinated polyethylene, 
chlorinated polypropylene, polyesters, polyamides, polyurethanes, 
polycarbonates, cellulose ether (e.g., ethyl cellulose) and cellulose 
esters (e.g., triacetyl cellulose, diacetyl cellulose, cellulose acetate 
butyrate). 
An acidic group is preferably introduced into the above-mentioned 
hydrophobic (cross-linkable or non-crosslinkable) polymer. Examples of the 
acidic functional groups include carboxyl, an acid anhydride group, 
phenolic hydroxyl, sulfo, sulfonamido and sulfonimido. The acidic 
functional groups can be introduced into the polymer by copolymerization 
with an acidic monomer. Examples of the acidic monomers include acrylic 
acid, methacrylic acid, styrenesulfonic acid and maleic anhydride. The 
amount of the monomer having the acidic functional group is preferably in 
the range of 1 to 60 mol %, more preferably in the range of 5 to 50 mol % 
and most preferably in the range of 10 to 40 mol %. 
The molecular weight of the hydrophobic polymer is preferably in the range 
of 1,000 to 500,000. Two or more polymers can be used in combination. 
Base or base precursor 
The light-sensitive material preferably contains a base or base precursor. 
Various organic or inorganic bases and their precursors (e.g., 
decarboxylation type, thermal decomposition type, reaction type, complex 
salt-formation type, dissociation type) can be used in the light-sensitive 
material. A base precursor is preferred to a base in view of stability of 
the light-sensitive material. 
An example of the decarboxylation type base precursor is a salt of an 
organic acid with a base that is decarboxylated under heating (described 
in Japanese Patent Provisional Publication Nos. 59(1984)-180537, 
61(1986)-313431, 63(1988)-316760, 64(1989)-68746). An example of the 
thermal decomposition type base precursor is a urea compound (described in 
Japanese Patent Provisional Publication No. 63(1988)-96159). An example of 
the reaction type base precursor is a transition metal acetylide 
(described in Japanese Patent Provisional Publication No. 63(1998)-25208). 
An example of the complex salt-formation type base precursor is a 
water-insoluble basic metal compound (described in Japanese Patent 
Provisional Publication No. 1(1989)-3282). An example of the dissociation 
type base precursor is an alkali metal salt of an organic acid (e.g., 
sodium acetate, sodium salt of a polymer having an acidic group). 
The base precursor preferably releases a base at a temperature in the range 
of 50 to 200.degree. C., and more preferably in the range of 80 to 
160.degree. C. 
The base or the base precursor is preferably used in an amount of 
preferably 0.1 to 20 mol, and more preferably 0.2 to 10 mol based on 1 mol 
of silver halide. 
Heat development accelerator 
The light-sensitive material can contain a heat development accelerator. 
The heat development accelerator may be added to any layers of the 
light-sensitive material. The heat development accelerator has a function 
of increasing the plasticity of a polymer (contained in the hardening 
layer or the light-sensitive layer). The accelerator has another function 
of accelerating the dispersion of the components in the layers when it is 
dissolved by heat of the development process. 
The heat development accelerator has been known as a plasticizer. The known 
plasticizers are described in Plastic Additives (written in Japanese), 
pages 21 to 63 (Taisei-sha); Plastics Additives, Second Edition; Hanser 
Publishers, Chapter 5, pages 251 to 296. 
Examples of the heat development accelerators include polyethers (e.g., 
polyethylene glycol, polypropylene glycol), polyhydric alcohols (e.g., 
glycerol, hexanediol), saccharides (e.g., sorbitol), formic esters, ureas 
(e.g., urea, diethylurea, ethyleneurea), amides (e.g., acetamide, 
propionamide, malonamide), sulfonamides, urea resins and phenol resins. 
Two or more heat development accelerators can be used in combination. The 
heat development accelerators can be added to two or more layers of the 
light-sensitive material. 
The amount of the heat development accelerator is preferably in the range 
of 0.05 to 2 g per m.sup.2, and more preferably in the range of 0.1 to 1 g 
per m.sup.2. 
Colorant 
The light-sensitive material can contain a colorant. The colorant can 
functions as an antihalation or antiirradiation dye. Further, a hardened 
image can be colored with the colorant. Various known dyes and pigments 
can be used as the colorant provided that the colorant does not affect the 
sensitivity and the developing reaction of silver halide. The hue of the 
antihalation or antiirradiation dye is preferably adjusted within the 
sensitive light region of silver halide. 
The colorants (dyes, pigments, colloidal silvers) are described in various 
publications such as Japanese Patent Provisional Publication No. 
5(1993)-249667, Handbook of Color Index and New Handbook of Pigments, 
Nippon Ganryo Gijutsu Kyokai (1970). 
The antiirradiation dyes having little effects on the sensitivity of silver 
halide are described in Japanese Patent Publication Nos. 41(1966)-20389, 
43(1968)-3504, 43(1968)-13168, Japanese Provisional Publication No. 
2(1990)-39042, U.S. Pat. Nos. 2,865,752, 3,423,207, 3,697,037, and British 
Patent Nos. 1,030,392, 1,100,546. 
The amount of the colorant is usually in the range of 0.01 to 2 g per 
m.sup.2, and preferably in the range of 0.05 to 1 g per m.sup.2. 
Development stopping agent 
The development stopping agent can be used in the light-sensitive material 
to obtain a clear image constantly regardless of the temperature and time 
for the development process. The development stopping agent can be a 
compound having a function of neutralizing a base or reacting with a base 
to reduce the base concentration in the layer to stop development. The 
agent can also be a compound having a function of mutually reacting with 
silver or a silver salt to suppress development, after the appropriate 
development. 
Examples of the development stopping agents include acid precursors capable 
of releasing acids upon heating, electrophilic compounds capable of 
undergoing substitution reaction with a coexisting base upon heating, 
nitrogen-containing heterocyclic compounds, mercapto compounds, and 
precursors thereof. The development stopping agents are described in 
Japanese Patent Provisional Publication Nos. 62(1987)-253159, 
2(1990)-42447 and 2(1990)-262661. 
Surface active agent 
A surface active agent can be added to a layer of the light-sensitive 
material. Various nonionic, anionic, cationic or fluorine surface active 
agents can be used. The surface active agent is described in Japanese 
Patent Provisional Publication No. 2(1990)-195356. Sorbitan, 
polyoxyethylene and a fluorine-containing compound are preferred. 
Matting agent 
A matting agent can be added to a back layer, an overcoating layer or an 
image formation accelerating layer to prevent adhesion of between two 
light-sensitive materials when the materials are superposed. 
Inorganic or organic solid particles can be used as the matting agent. 
Examples of the matting agents include oxides (e.g., silicon dioxide), 
alkali earth metal salts, natural polymers (e.g., starch, cellulose) and 
synthetic polymers. 
The average particle size of the matting agent is preferably in the range 
of 1 to 50 .mu.m. The amount of the matting agent is preferably in the 
range of 0.01 to 1 g per M.sup.2. 
Polymerization inhibitor 
A polymerization inhibitor can be added to the polymerizable layer to 
prevent a polymerization reaction while storing the light-sensitive 
material. Examples of the polymerization inhibitors include nitrosoamines, 
ureas, thioureas, thioamides, phenols and amines. 
Exposing step 
The silver halide light-sensitive is imagewise exposed to light. 
The wavelength of the light corresponds to the spectral sensitivity of 
silver halide. The wavelength is usually within the visible, near 
ultraviolet and near infrared regions. A X-ray and an electron bean can 
also be used as the light. 
Examples of the light sources include a tungsten lamp, a halogen lamp, a 
xenon lamp, a xenon flash lamp, a mercury lamp, a carbon arc lamp, various 
laser means (e.g., semiconductor laser, helium neon laser, argon ion 
laser, helium cadmium laser), light emitting diode and cathode-ray tube. 
The amount of the exposure is usually in the range of 0.001 to 1,000 .mu.J 
per cm.sup.2, and preferably in the range of 0.01 to 100 .mu.J per 
cm.sup.2. The light-sensitive material can be exposed to light through a 
transparent support. 
The exposure of silver halide, namely formation of latent image is 
influenced with the temperature and humidity at the exposing step. 
Accordingly, the sensitivity depends on the temperature and humidity. 
Therefore, the temperature and the humidity under the circumstances of the 
light source and the light-sensitive material are preferably controlled at 
constant values. An image recording apparatus having a controlling device 
is disclosed in Japanese Patent Provisional Publication Nos. 3(1991)-63143 
and 3(1991)-63637. 
Developing step 
The light-sensitive material is developed simultaneously with or after the 
exposing step. The light-sensitive material is preferably heated to 
develop the silver halide. 
The heat development can be conducted by placing the light-sensitive 
material on a heated material (e.g., metal plate, block, roller). The 
light-sensitive material may be immersed in a heated liquid for the 
development. Further, the light-sensitive material may be irradiated with 
an infrared ray. 
The surface of the light-sensitive material may be open to the air while 
heating the material from the side of the support. The surface of the 
light-sensitive material may be covered with the heating means to prevent 
the air from penetrating into the layers. 
The heating temperature is preferably in the range of 60 to 200.degree. C., 
and more preferably in the range of 100 to 150.degree. C. The heating time 
is preferably in the range of 1 to 180 seconds, and more preferably in the 
range of 5 to 60 seconds. 
A preheat treatment or post-heat treatment can be conducted before or after 
the heat development. The temperature of the preheat is lower than the 
heat development temperature, and the time is shorter than the development 
time. The post-heat treatment can be conducted after the image is formed, 
for example after removing the unhardened hardening layer. 
Removing step 
The unhardened area can be selectively removed to form a polymer image 
based on a difference in the solubility between the hardened area and the 
unhardened area. Before the removing step, hydrophilic layers 
(light-sensitive layer, adhesive layer, image formation accelerating 
layer) are preferably removed from the light-sensitive material. 
The light-sensitive material is immersed in a solvent (an etching solution) 
to conduct the removing step. An alkaline solution is preferably used as 
the solvent. 
Examples of the alkaline compound include sodium hydroxide, potassium 
hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium 
metasilicate, potassium metasilicate, sodium phosphate, potassium 
silicate, ammonia and aminoalcohols (e.g., monoethanolamine, 
diethanolamine, triethanolamine). 
The solvent preferably is water. An organic solvent can be used in 
combination with water. An alcohol and an ether are preferably used as the 
organic solvent. Examples of the alcohols include lower alcohols (e.g., 
methanol, ethanol, propanol, butanol), alcohols having an aromatic group 
(e.g., benzyl alcohol, phenethyl alcohol), polyhydric alcohols (e.g., 
ethylene glycol, diethylene glycol, triethylene glycol, polyethylene 
glycol) and aminoalcohols described above as the alkaline compounds. 
Examples of the ethers are cellosolves. 
The solvent may further contain the other additives such as a surface 
active agent and a defoaming agent. 
The obtained image can be used as a printing plate, a color proof, a hard 
copy or a relief image. 
Use of silver halide light-sensitive material 
The silver halide light-sensitive material can be used to prepare a hard 
copy, a relief image or a printing plate. The light-sensitive material of 
the present invention is advantageously used for the preparation of a 
printing plate. 
EXAMPLE 1 
Preparation of aluminum support 
A surface of an aluminum plate (according to JIS-A-1050) having the 
thickness of 0.24 mm was ground using a nylon brush and an aqueous 
suspension of pumice stone of 400 mesh. The plate was well washed out with 
water. The aluminum plate was then immersed for etching in 10% aqueous 
solution of sodium hydroxide at 70.degree. C. for 60 seconds. The plate 
was washed out with running water, then neutralized with 20 wt. % aqueous 
solution of nitric acid and washed out with water. 
The obtained aluminum plate was subjected to an electrolytic 
surface-roughening treatment in 1 wt.% aqueous solution of nitric acid 
containing 0.5 wt.% aluminum nitrate in an anodically electric amount of 
160 coulomb per dm.sup.2 using sine wave alternating-corrugated current 
under such conditions as an anodic voltage of 12.7 V and a cathodically 
electric amount ratio to an anodically electric amount of 0.9. The center 
line average height (Ra) of the aluminum plate was 0.6 .mu.m. 
The aluminum plate was immersed in 1 wt. % aqueous solution of sodium 
hydroxide at 40.degree. C. for 30 seconds. The plate was then immersed in 
30 wt. % sulfuric acid at 55.degree. C. for 1 minute. Further, the plate 
was subjected to anodizing treatment in 20 wt. % aqueous solution of 
sulfuric acid at a current density of 2 A per dm.sup.2 to form an anodic 
oxide layer having the thickness of 2.5 g per dm.sup.2. The plate was 
washed with water and dried to obtain an aluminum support. 
Preparation of pigment dispersion 
The following pigment dispersion was prepared. 
______________________________________ 
Pigment dispersion 15 g 
Copper phthalocyanine 
Allyl methacrylate/methacrylic acid copolymer 15 g 
(copolymerization ratio = 80/20) 
Methyl ethyl ketone 70 g 
______________________________________ 
Formation of hardening layer 
The following coating solution was coated and dried on the support to form 
a hardening layer having the dry thickness of 1.8 .mu.m. 
______________________________________ 
Coating solution of hardening layer 
2.0 g 
Pentaerythritol tetraacrylate 
Allyl methacrylate/methacrylic acid copolymer 4.0 g 
(copolymerization ratio = 70/30) 
Phenol compound (7) 0.31 g 
Propylene glycol monomethyl ether 36.0 g 
The pigment dispersion 18.0 g 
______________________________________ 
Preparation of silver halide emulsion 
Gelatin, potassium bromide and water were placed in a vessel, and the 
mixture in the vessel was heated to 55.degree. C. The following thioether 
compound (2.0.times.10.sup.-3 mol based on the total amount of silver 
nitrate) was added to the vessel. Further, an aqueous solution of silver 
nitrate and an aqueous solution of potassium bromide containing a rhodium 
ammonium chloride (the molar ratio of rhodium to the total amount of 
potassium iodide and silver nitrate is 4.times.10.sup.-8 mol) were added 
to the vessel according to a pAg controlled double jet method while 
keeping the pAg of 9.2 in the reaction vessel to prepare a silver 
iodobromide emulsion. Further, a potassium bromide solution containing 
hexachloroiridate(III) salt (the molar ratio of iridium to silver is 
10.sup.-7 mol) was twice added to the emulsion at 55.degree. C. and pAg 
8.9 according to a double jet method to obtain a core-shell type silver 
iodobromide emulsion having the following composition. 
(Thioether compound) 
EQU HO--CH.sub.2 CH.sub.2 --S--CH.sub.2 CH.sub.2 --S--CH.sub.2 CH.sub.2 --OH 
Core: Silver iodobromide (silver iodide content: 7.5 mol%) 
Shell: Pure silver bromide 
Core/shell: 3/7 (molar ratio of silver) 
Average silver iodide content: 2.3 mol % 
Average grain size: 0.28 .mu.m 
The grains of the obtained emulsion were monodispersed. In the emulsion, 
98% of the grains have a grain size within the range of the average grain 
size .+-.40%. 
After the emulsion was desalted, a methanol solution of the following 
sensitizing dye A (concentration: 5.times.10.sup.-3 M per liter, amount: 
100 ml per 1 mol of silver nitrate) and a methanol solution of the 
following sensitizing dye B (concentration: 5.times.10.sup.-3 M per liter, 
amount: 100 ml per 1 mol of silver nitrate) was added to the emulsion. The 
emulsion was left for 20 minutes. The emulsion was adjusted to pH 6.2 and 
pAg 8.7. The emulsion was subjected to a gold-sulfur sensitization using 
sodium thiosulfate and chloroauric acid to prepare a silver halide 
emulsion. 
##STR7## 
Preparation of reducing agent dispersion 
In 90 g of 10 wt. % aqueous solution of polyvinyl alcohol having the 
saponification degree of 88% (PVA-205, Kuraray Co., Ltd.), 10 g of powder 
of the following reducing agent was dispersed by using a dynomill 
dispersing device. The particle size of the reducing agent was not larger 
than about 0.5 .mu.m. 
##STR8## 
Formation of light-sensitive layer 
The following coating solution was coated and dried on the hardening layer 
to form a light-sensitive layer having the dry thickness of 1.3 .mu.m. 
______________________________________ 
Coating solution of light-sensitive layer 
______________________________________ 
10 Wt. % aqueous solution of polyvinyl alcohol having 
10.5 g 
the saponification degree of 88% (PVA-205, Kuraray Co., 
Ltd.) 
0.11 Wt. % agueous solution of the following additive 0.41 g 
The silver halide emulsion 0.50 g 
5 Wt. % aqueous solution of the following surface ac- 0.40 g 
tive agent 
Water 7.80 g 
The reducing agent dispersion 1.20 g 
______________________________________ 
##STR9## 
Preparation of base precursor dispersion 
In 750 g of 3 wt. % aqueous solution of polyvinyl alcohol (Kuraray Co., 
Ltd.) was dispersed 250 g of powder of the following base precursor by 
using Dynomill dispersing device. The particle size of the base precursor 
was not larger than about 0.5 .mu.m. 
##STR10## 
Formation of overcoating layer 
The following coating solution was coated and dried on the light-sensitive 
layer to form an overcoating layer having the dry thickness of 3.5 .mu.m. 
______________________________________ 
Coating solution of overcoating layer 
______________________________________ 
10 Wt. % aqueous solution of polyvinyl alcohol having 
200.0 g 
the saponification degree of 98.5% (PVA-105, Kuraray Co., 
Ltd.) 
The base precursor dispersion 1.25 g 
5 Wt. % aqueous solution of the surface active agent 4.0 g 
______________________________________ 
Preparation of alkaline solution 
The following alkaline solution was prepared and adjusted to pH 13.5. 
______________________________________ 
Alkaline solution 
______________________________________ 
28 Wt. % aqueous solution of potassium silicate 
125.0 g 
Potassium hydroxide 15.0 g 
Water 750.0 g 
______________________________________ 
Image formation 
The silver halide light-sensitive material was exposed to light of 670 nm 
through a control wedge (Fuji Photo Film Co., Ltd.), which was attached to 
the surface of the material. The light source was a xenon flush lump. The 
light of 670 nm was spectrally filtered through a sharp cut interference 
filter. The light emission time was 10.sup.-4 second. The exposure (energy 
on the surface) was 2 .mu.J per cm.sup.2. 
The aluminum support of the light-sensitive material was placed on a hot 
plate. The material was conveyed on the plate to heat the material for 30 
seconds. Thus the light-sensitive material was developed. 
The light-sensitive material was washed with water to remove the 
overcoating layer and the light-sensitive layer. The hardening layer was 
etched with the alkaline solution by a brush in an automatic developing 
machine. The light-sensitive material was well washed with water to form a 
blue polymer relief image within the exposed area of the hardening layer. 
The experiment was repeated while changing the heating temperature. As a 
result, a clear image was obtained when the heating temperature 
(temperature on the surface of the light-sensitive material at the heat 
development) was 143.degree. C. or higher. The clear image means an image 
in which 3% small dots of 200 line per inch can be observed. 
COMISON EXAMPLE 1 
A silver halide light-sensitive material was prepared and evaluated in the 
same manner as in Example 1, except that the phenol compound (7) was not 
used in the coating solution of the hardening layer. As a result, the 
clear image defined in Example 1 was obtained when the heating temperature 
was 150.degree. C. or higher. The results of Example 1 and Comparison 
example 1 confirm that the phenol compound (7) has a function of lowering 
the heating temperature by 7.degree. C. 
EXAMPLES 2 to 12 
Silver halide light-sensitive materials were prepared and evaluated in the 
same manner as in Example 1, except that the phenol compounds shown in 
Table 1 was used in place of the phenol compound (7). The amounts of the 
phenol compounds were the same as the amount of the phenol compound (7). 
The results are set forth in Table 1. In Table 1, the results of Example 1 
and Comparison Example 1 are set forth again. 
TABLE 1 
______________________________________ 
Light- Lowest heating 
sensitive temperature for 
material Phenol compound forming a clear image 
______________________________________ 
Comp. 1 None 150.degree. C. 
Example 1 (7) 143.degree. C. 
Example 2 (1) 145.degree. C. 
Example 3 (4) 145.degree. C. 
Example 4 (5) 145.degree. C. 
Example 5 (6) 143.degree. C. 
Example 6 (8) 145.degree. C. 
Example 7 (9) 145.degree. C. 
Example 8 (10) 145.degree. C. 
Example 9 (11) 145.degree. C. 
Example 10 (14) 145.degree. C. 
Example 11 (20) 145.degree. C. 
Example 12 (27) 145.degree. C. 
______________________________________ 
EXAMPLE 13 
The silver halide light-sensitive material prepared in Example 1 was 
exposed to light of 670 nm. The light source was a xenon flush lump. The 
light of 670 nm was spectrally filtered through a sharp cut interference 
filter. The light emission time was 10.sup.-4 second. The exposure (energy 
on the surface) was 2 .mu.J per cm.sup.2. 
The aluminum support of the light-sensitive material was placed on a hot 
plate. The material was conveyed on the plate to heat the material for 30 
seconds. Thus the light-sensitive material was developed. 
The light-sensitive material was connected to an electrode of an LCR meter 
(4263A, Hewlett Packard). The other electrode was connected to an aluminum 
plate. The light-sensitive material and the aluminum plate were immersed 
in the alkaline solution used in Example 1. After 3 minutes, the current 
was measured to evaluate permeation of the solution into the hardened 
image. 
The experiment was repeated while changing the heating temperature. As a 
result, permeation was not observed (namely the image was sufficiently 
hardened) when the heating temperature (temperature on the surface of the 
light-sensitive material at the heat development) was 145.degree. C. or 
higher. 
COMISON EXAMPLE 2 
The silver halide light-sensitive material prepared in Comparison Example 1 
was evaluated in the same manner as in Example 13. As a result, permeation 
was not observed (namely the image was sufficiently hardened) when the 
heating temperature (temperature on the surface of the light-sensitive 
material at the heat development) was 155.degree. C. or higher. The 
results of Example 13 and Comparison example 2 confirm that the phenol 
compound (7) has a function of lowering the heating temperature. 
EXAMPLE 4 
A hardening layer was formed on an aluminum support in the same manner as 
in Example 1. The following coating solution was coated and dried on the 
hardening layer to form a light-sensitive layer having the dry thickness 
of 3.5 .mu.m. The obtained light-sensitive material was evaluated in the 
same manner as in Example 1. As a result, the clear image defined in 
Example 1 was obtained when the heating temperature was 145.degree. C. or 
higher. 
______________________________________ 
Coating solution of light-sensitive layer 
______________________________________ 
10 Wt. % aqueous solution of polyvinyl alcohol having 
200.0 g 
the saponification degree of 98.5% (FVA-105, Kuraray Co., 
Ltd.) 
0.11 Wt. % aqueous solution of the additive used in 0.41 g 
Example 1 
The silver halide emulsion used in Example 1 0.50 g 
5 Wt. % aqueous solution of the surface active agent 4.40 g 
used in Example 1 
Water 7.80 g 
The reducing agent dispersion used in Example 1 1.20 g 
The base precursor dispersion used in Example 1 1.25 g 
______________________________________